Its cathedral episcopal see is the Cathédrale de l’Immaculée Conception, dedicated to the Immaculate Conception at Nkongsamba, in Moungo Department in the Littoral Region (Cameroon).
Established on April 28, 1914, as Apostolic Prefecture of Adamaua, an immense territory on the Adamawa Pateau, split off from the much vaster still Apostolic Vicariate of Khartoum, in the then Anglo-Egyptian Sudan.
Renamed on June 11, 1923, as Apostolic Prefecture of Foumban, after its see F(o)umban.
Promoted on May 28, 1934, as Apostolic Vicariate of Foumban, hence entitled to a (titular) bishop.
It lost territory repeatedly : On September 14, 1955, it was promoted and renamed as Diocese of Nkongsamba after its present see.