The B-534 saw combat with the Slovak Air Force, the Bulgarian Air Force, and was used for training and other duties by the Luftwaffe.

The B-534-I was armed with 2 x 7.92 mm machine guns.
The B-534-II was armed with 4 x 7.92 mm machine guns.
The B-534-III was armed with 4 x 7.92 mm machine guns. It also had a revised air intake and wheel fairings.
The B-534-IV was armed with 4 x 7.92 mm machine guns. It also had an enclosed cockpit along with the revisions on Type III.

There were exceptions to these general versions, and pilots sometimes made 'field modifications' including removing the enclosed cockpit and wheel fairings.