Ar 64a Prototype, powered by a 395 kW (530 hp) Bristol Jupiter VI nine-cylinder radial. First flight in 1930. One built
Ar 64b Only two built powered by a 477 kW (640 hp) BMW VI 6.3 12-cylinder V-type water-cooled engine. First flight in 1931. Two built.
Ar 64c Powered by a 395 kW (530 hp) Jupiter VI radial, but with minor structural changes. One built.
Ar 64D Production model. Featured redesigned, and enlarged vertical tail surfaces and a revised undercarriage. Powered by a geared Jupiter VI radial.
Ar 64E Production model. Similar to the 64d but with a direct drive version of the Jupiter VI radial. A total of 20 D and E model Ar 64s were built.