- The Assembly of Heads of states and government.
- The Council of Ministers.
- The General Secretariat.
- The Commission for Mediation, Conciliation and Arbitration.
The first Secretary-General of the OAU was Diallo Telli of Guinea, who held the post from 1963-1972.
Other Secretaries-General of the organization are: Ezo Ekangaki of Cameroun (1972-1974), William Eketi Mbomoua of Cameroun (1974-78), Eden Kodjo of Togo (1978-83), Peter Onu of Nigeria (1983-85), Ide Omarou of Niger Republic (1985-89), Salim Ahmed Salim of Tanzania (1989-2001), Amara Essy etc.