Sharing basic components with the Ca 134 reconnaissance biplane, the Ca 165 single-seat fighter was an anachronism which appeared in numerous publications during the Second World War but never entered service with the Regia Aeronautica. It was powered by a 900 h.p. Isotta-Fraschini Asso L.121 R.C.40 twelve-cylinder engine. Although the wings were nearly identical in structure to those of the Ca 134, they were unstaggered, necessitating a different bracing arrangement. The N-struts of the reconnaissance plane were replaced by single faired I outer struts on the fighter. The prototype Ca 165 had a "solid" fairing from the cockpit back to the fin, while the later versions had all-transparent canopies. Two 7.7-mm. machine guns mere mounted in the cowl firing through the airscrew disc.
Performance included a maximum speed of 280 m.p.h. at 16,400 ft., with cruising and landing speeds of 235 m.p.h. and 68 m.p.h. respectively. Service ceiling was 32,800 ft. Dimensions were: span 30 ft. 6 1/4 in., length 26 ft. 6 7/8 in., and height 8 ft. 4 1/2 in.