Staffel flew combat missions in the Invasion of Yugoslavia. The next day, the Staffel flew combat air patrols on the Hungarian-Yugoslavian border. On 9 April, II./JG 54 was united again at Kecskemét, Hungary and returned to Deta on 11 April.
A squadron of the Staffel engaged in combat flights during Yugoslavia's invasion. The following day, they conducted air surveillance along the Hungarian-Yugoslav border. On 9 April, II./JG 54 was reunited at Kecskemét, Hungary, and returned to Deta on 11 April.