Here is a list of all the items you need for the 100%. You can purchase treasure maps from the Merchant to show treasures on your in game map. I made some notes for treasure checks so you don't forget to collect them before moving on. I have also included chapter specific achievements so you can go for them as you play.

Labels are as follows:
W = Weapon
CC = Clockwork Castellans
MR = Merchant Request
A = Chapter specific achievement
K = Small key
U = Weapon part (not needed for any achievement)

Also, I did not include items unlocked or purchased from the Merchant. You can get them at any time. This is for missable items you need to worry about.

There are 3 loot based weapons: hand grenades, heavy grenades, and flash grenades. You'll easily get these as you play.

I have listed all collectables required for achievements. If you want every single item in the game and a video walkthrough, I included a 2 hour long guide created by PowerPyx towards the bottom of the next collectables section. All 293 collectables can be found there.

Chapter 1
W - W-870 Shotgun: On the 2nd floor of the only 2 story house in the Village during the holdout section.

MR - Destroy the Blue Medallions: At the end of the the next area, the request is on the wall before the closed gate. The locations now appear on your map.

W - Kitchen Knife: Inside the barn in the north-east of the area near the Wooden Cog.

CC - After encountering dynamite throwers, it's in the house in the center of the area, sitting on the broken roof.

Chapter 2
Note: Buy the Village treasure map from the Merchant.

MR - Pest Control: Next to the first Merchant. Rats 1 and 2 are in the room where you have the parry tutorial. Rat 3 is in the destroyed hallway.

K - Inside the shack underneath the Hexagonal Emblem. Unlock the drawer where you retrieved your items.

CC - After using the Hexagonal Emblem, and walking up some stairs, enter the hut on the left. It's above you.

K - In the Village Chief’s Manor. In the corner on the 1st floor. Unlock the drawer in the village.

Note: Map treasure check.

Chapter 3
Note: Map treasure check after going back to the village.

MR - Viper Hunter: Near the Merchant after leaving Town Hall. You need to sell 3 Vipers. About 6 can be found at the Fish Farm when looking for boat fuel.

MR - Grave Robber: While in the graveyard before the church, shoot the V-emblems on the double graves near the center.

MR - Destroy the Blue Medallions 2: Along the main path after entering The Quarry with a bunch of birds, it's on the wall.

Note: Grab the Hexagon Piece in the chest near the Merchant after the Quarry.

CC - Jump down the ladder near the Merchant. Go to the end of the pier and look up to see it between the roof and wooden boxes.

K - Inside a drawer in the western corner of the Fish Farm. Unlock the drawer near the Merchant at the boat dock.

Note: Another Hexagon Piece is found in the north west part of the Fish Farm.

Chapter 4
Note: Pick up the Old Wayshrine key in a chest to your right after exiting the cave.

MR - Egg Hunt: The shore on the east side of the lake has a chicken farm with a golden egg you need to sell for a MR.

MR - Catch Me A Big Fish: After gaining control of the boat, harpoon the Lunker Bass at the Boat House. Sell it to complete a MR.

W - Red9 Pistol: Found in the middle of the lake on a shipwreck.

Note: The final Hexagon Piece is in the north east area of the lake at the Small Cave Shrine. Use them at the treasure location opposite of the boat before you fought the lake boss.

CC - At the Lakeside Settlement. Use the Insignia Key on the locked gate and climb the ladder behind it. This leads to a Forest Altar area. The Castellan can be shot through a fence.

K - While at the alter, grab the key on top of a carriage. Unlock the drawer above where you met Luis.

Bonus item: A Rhinoceros Beetle can be found on a tree where you first entered this area. It allows you to purchase an in game model and is used to increase your maximum health.

Note: Map treasure check before going to the church.

K - Once inside the church, the key will be next to the pedestal at the front. Unlock the drawer in the save room outside the church.

Chapter 5
MR - A Savage Mutt: On the wall next to the Merchant outside Town Hall. To spawn the boss, go south to Village Chief’s Manor and explore the attic. Return to the Village and it will spawn.

CC - While at Village Chief’s Manor, in the attic. Pull the lever and boost Ashley up the ladder. It’s on the left side of the attic, behind a yellow destructible crate.

Note: Map treasure check before the cabin holdout section.

Chapter 6
CC - Along a hill path after the first few enemies. The Castellan is to the right under a bonfire. Just before reaching the “Checkpoint” area.

Note: Map treasure check before Mendez AND before moving on to the castle.

Chapter 7
Note: Purchase the Castle treasure map from the Merchant.

W - Boot Knife: Dropped by the first enemy in Chapter 7, encountered in the Chapel.

A - Overkill: Use the cannon to kill a zealot.

MR - Destroy the Blue Medallions 3: Just before entering the Castle, the request is to the right of the door.

A - Never Heard It Coming: Defeat a Garrador using only Knives.

CC - After the Garrador encounter (blind guy with claws), and going upstairs to the storage room, the Castellan is on top of a shelf.

Note: Map treasure check.

Chapter 8
MR - Jewel Thief: After gaining control of Leon, look towards the gate leading to the Merchant. Above it is a nest, shoot it and pick up the emerald. Sell it to complete a MR.

Note: Another rhinoceros beetle is on a wall to the left area with fish swimming around.

K - After the Bindery puzzle (puzzle after cutscene with Ada), you’ll end up in an L-shaped corridor. The key is on a table to your left after Leon says "Oh great". Unlock the drawer in the next area, NOT the drawer behind you.

CC - Drop down the right side of the tower going west when the Beast Titan Giant starts throwing rocks at you. Enter the tower and go up to the rooftop. Circle around the tower to find the Castellan at the end.

Note: Map treasure check.

Chapter 9
CC - In the northwest corner of the courtyard maze.

MR - Destroy the Blue Medallions 4: In the typewriter save room with Merchant on the table.

MR - More Pest Control: On the wall left of the Headless Statue. Rat 1 is in the Dining Hall just after picking up the request. Rat 2 is in the hallway after fighting the 6 knights, near the Cubic Device. Rat 3 is at the start of Chapter 10.

K - Inside a cupboard on the upper left corner of the hall with suits of armor. Ashley will comment saying you could wear one as armor. Unlock the drawer in the Bindery puzzle room.

Final notes:
- Pick up the Cubic Device in the chest after defeating the knights and get rat 2.

- BEFORE using the 3 statue head pieces, backtrack to where you first met the Zealot in red robes! You need Ashley for a treasure there.

- Map treasure check

As Ashley:
Use the Bunch of Keys to get all 3 treasures. These are missable! The locations are: the library, room after the cutscene with Leon, and before the lantern puzzle. The keys can be skipped by solving the clock puzzle without getting the note. So don't solve the puzzle before obtaining the keys.

Chapter 10
MR - Merciless Knight: In the room to the right of the 3-headed statue. On a drawer is the request. Backtrack to the Mausoleum and defeat the knights.

Rat 3 is in the room to the right of the 3-headed statue. Enter the dark hallway on the right to find the rat.

W - CQBR Assault Rifle: In the library, go upstairs and use the Cubic Device on the Square Lock Box.

Note: Map treasure check.

CC - Outside the Merchant in the sewers. You can see its head behind the bars hanging upside down.

A - Wave Goodbye, Right Hand: Defeat the Verdugo (boss in the sewers) before taking the elevator.

Note: Map treasure check BEFORE taking the elevator.

Chapter 11
Note: Map treasure check BEFORE using the dynamite.

A - Hope You Like Thrill Rides!: Make it through both minecart sections in the underground tunnel without taking damage.

CC - After the first minecart ride, on top of the building wall. You can shoot it from inside the building. Get it before getting on the 2nd minecart. There is also a treasure here to collect.

MR - Insect Hive: In the east of the “Hive” area after the cart section. The request is hanging on a wooden pallet behind an explosive barrel. You must destroy all 4 entrances to the Hive. They are the yellow glowing sacks on the ceiling in the middle of the area.

Note: Map treasure check BEFORE taking the elevator.

Chapter 12
K - Inside a briefcase behind the gondola that takes you to the clock tower. Unlock the drawer in the first room of the Castle.

MR - The Disgrace of the Salazar Family: The request is on the wall next to the gondola. Go to the Throne Room. Open the shrine in the room to get a golden chicken egg or wait for a chicken to lay an egg. Throw one at the painting of Salazar above the 2 red chairs.

Note: Collect any treasures and finish all requests BEFORE taking the gondola to the clock tower.

CC - After making it to the clock tower, it’s sitting on a box in the northwest corner of the room. Destroy it before going upstairs.

Note: Map treasure check BEFORE taking the lift.

A - Capacity Compliance: Reach the top of the clock tower without the lift stopping once.

Note: Map treasure check BEFORE the Salazar fight.

A - You Talk Too Much!: Throw a grenade into Ramón Salazar’s mouth.

Chapter 13
Note: Purchase the Island treasure map from the Merchant.

CC - Go through the gate after the rocket launcher enemies. In this area where the path splits, go down the right path. The Castellan in the right corner between a green forklift and an orange container-truck.

Note: Map treasure check.

W - LE 5: After getting the Level 1 Keycard, flip the Power Control Lever to reroute power to the left side. Then use Level 1 Keycard on the Freezer door. Solve the puzzle in the freezer to access the treasure behind the door.

U - Biosensor Scope: In the Incubation Lab. It will be on the table next to the card upgrading unit.

A - Two Bugs, One Stone: After obtaining the Biosensor scope, equip it to a sniper rifle. Then circle around the room and look at one of the regenerators in a pod. Line up a shot to destroy both parasites with one bullet and the achievement will unlock.

Chapter 14
MR - Destroy the Blue Medallions 5: At the entrance to the Merchant shop at the start of the chapter.

MR - Even More Pest Control: Picking up the request isn't necessary. Rat 1 is at the entrance of Waste Disposal. This is the after the second red gate you and Ashley flip switches to open. Rat 2 is immediately after the bridge Ashley can raise. Rats 3 and 4 are at the end of Waste Disposal where you flip the Power-Reroute switch.

MR - The Wandering Dead: Left on a box after entering the door Ashley opens with a wrecking ball. The enemy will be marked on the map. Do this before taking the lift up to the Amber Storeroom.

Note: Map treasure check BEFORE talking the lift.

CC - After the cutscene in Amber Storeroom, go through the gates and enter the tunnel. Walk south, then look to the right. It will be on some lockers in a small building just above the Campsite.

Note: Map treasure check BEFORE the Krauser fight.

Note: Another rhinoceros beetle is on the cliff wall behind you after the cutscene with Krauser.

Chapter 15
MR - Destroy the Blue Medallions 6: At the exit of “Cliffside Ruins” area. Destroy the medallions before proceeding through the door.

Note: Map treasure check.

CC - Found after the Ruins, in a room with body bags hanging from the ceiling. In the north of this area is a little room with the Castellan on wooden beams above a treasure chest.

Note: Map treasure check.

Chapter 16
Note: Final map treasure check.

CC - After the boss fight, during the timed escape sequence, it's on the right side of the rectangular room with enemies in it.

A - Smooth Escape: Escape on the water scooter without taking any damage.

NG+ weapons:
W - Infinite Rocket Launcher: Bought in NG+ for 2 Million ptas.

W - Chicago Sweeper: Unlocked by completing the game on Professional with an A rank. This can be done in NG+.

W - Handcannon: Unlocked by completing the game on Professional without using any NG+ weapons. This CANNOT be done in NG+, it needs to be a fresh save.

W - Primal Knife: Unlocked by finding all 16 Castellans.

Here is a complete video guide for all 293 items in Resident Evil 4 Remake:
https://www.youtube.com/watch?v=MoIu3DL-M_Y&t=1s&ab_channel=PowerPyx

Thank you, everyone, for checking out my guide. I make guides for games I also want all achievements in. I hope I was able to help you 100% Resident Evil 4 Remake. Be sure to let me know if I made a mistake or if something is not easy to follow! This way I can make the guide better! Thank you for the likes, favorites, awards, and for simply viewing this guide!

Many of you have probably seen some of my other guides. I try to make them as clear and concise as possible as to not waste your time with worthless information or pictures. Here are some others you might have seen:
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=2924328522
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=2896230238
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=2719012872
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=2763827450