In addition to use as an anti-aircraft gun, the Model 35 was mounted as the main armament in several vehicles. It was initially fitted in four Panzer Is converted during the Spanish Civil War, by the Nationalists, in an effort to improve their fighting capability against the Soviet T-26s fielded by the Republican forces. Later the gun was fitted to Fiat L6/40 light tanks and the AB 41 armoured cars. In addition, this gun was employed as a deck-mounted anti-aircraft weapon in at least some of the MAS torpedo boats. The naval mounting had an elevation of -10 to +90 degrees and it used the same sights as the land based version.
After the Winter War had begun, Finland bought a total of 88 Breda guns from Italy, the last arriving during the Interim Peace in June 1940. Five of the Finnish Bredas were later lost in action during the Continuation War. In addition, the four Italian-built Jymy class motor torpedo boats operated by the Finnish Navy each had one 20 mm Breda cannon on the rear deck. The Finnish Defence Forces used the 20 ItK/35 Breda, as the gun was officially known in that service, as a training weapon for anti-aircraft crews for several decades after the end of World War II. In 1985 there were still 76 guns remaining in the inventory, but all of these were discarded later during that decade.
In North Africa, the Commonwealth forces captured a large number of Breda Model 35s during Operation Compass, enabling the Australian 2/3 Light Anti-Aircraft Regiment, parts of the 4th Anti-Aircraft Brigade (which had a total of 42 Bredas in its Light Anti-Aircraft batteries during the Siege of Tobruk) and one battery of 106th (Lancashire Hussars) Regiment, RHA to be equipped with them.
Captured Bredas were used by the Long Range Desert Group and aboard a number of Royal Australian Navy and Royal Navy vessels including HMAS Vendetta, HMAS Perth and HMS Ladybird, and at least one Marmon-Herrington Mk II armoured car.
During the Second Sino-Japanese War (World War 2 in China), Chinese Nationalist Army soldiers used the Breda Model 35 during the Battle of Xinkou, shooting down 3 Japanese planes. The Breda Model 35 was not only used in the anti-aircraft role but was also used to destroy Japanese tanks and armored vehicles.