[1] It became the standard tank of the emerging Italian armored units after World War I.

The up-gunned version of the 3000, armed with a 37/40 gun, was tested in 1929 and was officially adopted in 1930 with the designation of carro d'assalto Fiat 3000, Mod.

[2] By turning the engine sideways for the first time (a principle still used on Russian tanks today) after slightly widening the hull, Italian engineers were able to make the fighting compartment much less cramped and the tank shorter and lighter at the same time.

[1] A limited number of Model 21 vehicles were exported to Albania, Latvia (6 in 1926),[5] Hungary, and Abyssinia (Ethiopia) prior to 1930.

With Italy's entry into World War II in June 1940, a limited number of Fiat 3000s still in service with the Italian Army were employed operationally on the Greek-Albanian front.