The KGB was organized into several directorates, with certain directorates assigned a “chief” status due to their importance.

The known directorates are:

The First Chief Directorate (Foreign Operations) — responsible for foreign operations and intelligence-gathering. This chief directorate had many sub-directorates of its own.

The Second Chief Directorate — responsible for counter-intelligence and internal political control of citizens and foreigners in the Soviet Union.

The Third Chief Directorate (Armed Forces) — controlled military counter-intelligence and the political surveillance of the Soviet armed forces.

The Fourth Directorate (Transportation Security)

The Fifth Chief Directorate — also responsible for internal security; originally combated political dissent; later assumed tasks of the Second Chief Directorate, such as controlling religious dissent, monitoring artists, and the censorship of media; it was renamed Directorate Z (to Protect the Constitutional Order) in 1989.

The Sixth Directorate (Economic Counterintelligence and Industrial Security)

The Seventh Directorate (Surveillance) — handled surveillance, providing equipment to follow and monitor activities of both foreigners and Soviet citizens.

The Eighth Chief Directorate — responsible for communications, monitoring foreign communications, and the cryptologic systems used by KGB divisions, KGB transmissions to overseas stations, and the development of communications technology.

The Ninth Directorate (Guards) (later the KGB Protection Service) — bodyguard services.

The Fifteenth Directorate (Security of Government Installations)

The Sixteenth Directorate (Communications Interception and SIGINT) — telephone and telegraph systems.

The Border Guards Directorate — 245,000-man border security force dealt with smuggling along the Soviet Union's borders with terrestrial, naval, and air force contingents.

The Operations and Technology Directorate - laboratories and scientific research centers.