In October 1974, Dyer was traded to the Pirates for Gene Clines. He backed up Manny Sanguillén and helped the Pirates win the 1975 National League Eastern Division. Dyer was the Pirates catcher on August 9, 1976, when John Candelaria pitched a no hitter against the Los Angeles Dodgers. In 1977 the Pirates traded away Sanguillen, and Dyer shared catching duties with Ed Ott in a platoon system. Dyer led National League catchers in 1977 with a .996 fielding percentage, committing only two errors in 93 games.