Designed to serve both as a fighter and an attack aircraft, it was a low-wing monoplane with a fixed landing gear of mixed construction, having trouser-covered legs.

In the same year, the Regia Aeronautica ordered a second series with improvements including a more powerful Alfa Romeo engine and more aerodynamic landing gear.

The Caproni AP.1 equipped a total of eight squadriglie (Italian air unit equivalent to half an RAF squadron) of the assault wings of the Regia Aeronautica.

Four examples were purchased by El Salvador in 1938 for use in the Escuadrilla de Caza of the Salvadoran Air Force, in response to Honduras buying North American NA-16.

Shortage of spare parts for the aircraft's engines and damage to the wooden structure due to the tropical conditions and termites limited serviceability by mid-1943, and they were withdrawn from use in December 1944.