Upon its introduction to squadron service with the Czechoslovak Air Force during the latter half of 1935, the B-534 was put to use in the interceptor role. Initially, the responsibility for pursuit and aerial combat was shared with several other aircraft, including the Avia BA-33L and the Letov Š-31; however, by 1938, the B-534 was the sole type of aircraft in Czech service to be tasked with this role. By 10 November 1938, a total of 370 B-534 and Bk-534 aircraft in service; additionally, 53 aircraft had been written off as a result of accidents.