Delta's main mission is counter-terrorism (CT). This includes:

- hostage rescue
- the capture / elimination of terrorist forces
- intelligence gathering on terrorist threats

Other roles include:

- close protection (guarding VIPs)
- unconventional warfare

Since their inception, Delta have become masters at the dark arts of counter terrorism. The unit's operators are highly skilled in sniping and close quarters combat (CQB), dynamic and covert entry, explosives and hand-to-hand combat. Over the years, Delta have developed a working knowledge of systems on aircraft, trains, ships and vehicles that enables them to intervene and take control of any scenario in any environment. Regular exercises with US and foreign CT units keeps their skill-set and knowledge-base up-to-date. A Delta Force team is reportedly on immediate standby to respond to a terrorist threat. Delta's CT role overlaps to some degree with the Navy unit, DEVGRU.