In 1959, Mamudu joined the Nigerian regiment and was trained at the Mons Officer Cadet School and the prestigious Royal Military Academy, Sandhurst.

Mamudu, being one of the few officers, advised his Eastern soldiers to refrain from reporting to work in order to ensure their safety, which allowed them to escape to Biafra.In 1960 he was assistant platoon leader under Yakubu Gowon platoon, during the Congo war.

Later he was appointed Military Administrator of Gongola State (25 July 1978 to 30 September 1979)[4] and a Commander of the Nigerian Army Signals Corps.

[5] He retired in 1983, after over twenty-three years of active military service and went into private enterprise as a stevedore.

Major General Abdulrahman Mamudu is from Agbede Town, Etsako West local government of Edo State.