After turning professional in 1974, Mark Pfeil played the PGA TOUR off and on from 1976 to 2001. He made 375 starts and captured one victory at the 1980 Tallahassee Open.

He earned 12 top-10 finishes and had his career-best year in 1984 when he finished 69th on the Official Money List with $101,878 in earnings.

After playing in two Champions Tour events in 2001, Mark joined the Tour in 2002 after finishing 15th in the 2001 Champions Tour Qualifying Tournament. He qualified again at the 2002 Tournament and played a second season in 2003. During his two seasons on the Champions Tour, Mark had seven top-25 finishes, including one top-10, a tie for 10th place at the 2002 NFL Golf Classic.