The prototype, which was first flown in September 1935, like the initial production aircraft, used the 522 kW (700 hp) Gnôme-Rhône K-14 radial engine produced under license by Isotta Fraschini.

Thirteen Series I aircraft, powered by the Gnôme-Rhône engine, equipped the 65a Squadriglia of the Aviazione Legionaria (Legionary Air Force).

In a unique engagement, one of the Legionary Air Force pilots scored an air-to-air victory when he encountered a lone twin-engine Tupolev SB bomber over Soria and shot it down.

The Ba.65 was used against armed forces of the United Kingdom and the Commonwealth of Nations which the coup leaders were trying to expel from bases established after Iraq's independence under the Anglo-Iraqi Treaty of 1930.

When Italy entered the war in June 1940 about 150 aircraft were reported to be still in service, but suffered heavy losses facing the British fighters.

The aircraft, which had been forcibly kept in service after the failure of the Ba.88 and the poor performance of the Caproni Ca.310, was replaced in the dive bomber role by modified Savoia-Marchetti S.79s or fighters.

Despite having been destined for scrap at the beginning of hostilities and pulled back into action, the Bredas of 50 Stormo fought a bitter and courageous battle from 13 June 1940 to the remainder of the year.

Antonio dell'Oro, Tenente Adriano Visconti and Spanish civil war veteran pilots who were properly trained to fly the aircraft it proved a bitter pill for British armoured forces caught in the desert.