Wilhelm pitched 44 games for the 1969 California Angels and had a 2.47 ERA, ten saves, and a 5–7 record. On September 8, 1969, Wilhelm and Bob Priddy were traded to the Atlanta Braves for Clint Compton and Mickey Rivers. He finished the 1969 season by pitching in eight games for the Braves, earning four saves and recording a 0.73 ERA over  innings pitched. Wilhelm then spent most of the 1970 season with the Braves, pitching in 50 games for the team and earning ten saves.