It was a sequel to G-Men vs. the Black Dragon released earlier in 1943, again starring Rod Cameron as American secret agent Rex Bennett.

In an attempt to control the entire Middle East and defeat the Allies, Nazi agent Baron von Rommler captures and impersonates Sultan Abou Ben Ali, leader of all the Arabs.

Opposed to him is Secret Service Agent Rex Bennett, along with British reporter and aviatrix Janet Blake and French Chief of Police in Casablanca, Captain Pierre LaSalle.

[1] The serial was re-released on April 5, 1954, under the new title Manhunt in the African Jungles, between the first runs of Trader Tom of the China Seas and Man with the Steel Whip.

[1] Secret Service in Darkest Africa was one of twenty-six Republic serials re-released as a film on television in 1966.

[1] Stedman compares Secret Service in Darkest Africa poorly to the first serial, G-Men vs. the Black Dragon, which was directed by William Witney.

Spencer Gordon Bennet, the director of this sequel, is blamed for this lapse, giving the serial a style similar to the Batman television series of the mid-1960s.

[5] In the words of Cline, both this serial and its predecessor were "well-made topical drama with highly capable and professional casts".