Gilliam was selected by the
Pittsburgh Steelers in the 11th round of the
1972 NFL draft, the 273rd overall pick. His first NFL game came on November 5, 1972, when he came on in relief of
Terry Bradshaw in a blowout win over the
Cincinnati Bengals with Pittsburgh's regular backup quarterback
Terry Hanratty injured. He made his first regular season start on
Monday Night Football, during a week 12 game against the
Miami Dolphins on December 3, 1973. The game was a disaster for Gilliam: he threw just seven passes, all incomplete and three intercepted by
Dick Anderson, including one for a Miami touchdown. Prior to the
1974 regular season, Steelers head coach
Chuck Noll stated that the starting quarterback position was "wide open" among
Terry Bradshaw, Gilliam, and
Terry Hanratty. Gilliam outperformed the other two in the 1974 pre-season and Noll named Gilliam the starting quarterback, the first
African American quarterback to start a season opener after the
AFL–NFL merger in
1970. After a 30–0 win in the season opener over
Baltimore, he was featured on the cover of
Sports Illustrated. Although he was 4-1-1 in the first six games, he was benched in late October for his lackluster performance and ignoring team rules and game plans. In particular, Gilliam ran afoul of Chuck Noll for his excessive number of pass plays. During the Week 2 game against
Denver Broncos, he threw a record 50 passes and almost totally ignored the run game, leading to a 35–35 tie. In Week 3, Gilliam delivered a terrible performance with only 8 completed passes in 31 attempts and 2 interceptions, leading to the Steelers suffering the humiliation of a home shutout by archrival
Oakland Raiders. After fans began demanding Terry Bradshaw's return, Gilliam was benched. He also received numerous death threats, some of them racially charged. Bradshaw returned as the starter on
Monday night in week 7 and led the team to a win in
Super Bowl IX, the first of four Super Bowl championships with him at the helm of the offense. "He gave me my job back," Bradshaw told sportscaster
James Brown on a February 2000 edition of
Real Sports with Bryant Gumbel on
HBO. He spent most of the
1975 season as the backup quarterback to Bradshaw but was demoted to 3rd string quarterback behind Hanratty after a poor performance at the end of the season against the
Los Angeles Rams and missing some team meetings. The 1975 season was his last on an NFL roster, as the team repeated as champions in
Super Bowl X. Gilliam felt that his demotion was based on racial reasons. In an interview with
The Tennessean a year before his death, he said "I thought if you played well, you got to play. I guess I didn't understand the significance of being a black quarterback at the time." Wide receiver
John Stallworth recalled that Gilliam's demotion was due to his poor on-field performance, disobeying Chuck Noll's game plan, and substance abuse issues and there was no racial motivation whatsoever on the team's part. He noted that Noll was "completely color-blind" as a coach and not racist in any way. Linebacker
Andy Russell said that Gilliam was "immensely talented" as a quarterback, but unable to stay off of drugs. The Steelers waived Gilliam prior to the 1976 preseason after he missed a team meeting. He battled
heroin,
cocaine, and alcohol addiction on and off over the next several years and even ended up living in a cardboard box under a bridge for two years. He was arrested in
New Orleans in 1976 for possession of a gun and cocaine. The
New Orleans Saints then signed Gilliam, but he was cut in both
1976 and
1977, then played with the semipro Pittsburgh Wolf Pak, but quit in August 1978, after playing in just six games. He returned to semipro in 1979 with the Baltimore Eagles in the Atlantic Football Conference, but his season would take a couple of bizarre turns: first, an abortive attempt to jump to the Alabama Vulcans of the
American Football Association ended when he borrowed the Vulcans' owner's Cadillac and failed to return it; then, after Gilliam went back to Baltimore, he was attacked by four men, who dragged him out of his parked car and repeatedly hit him on the head. Gilliam returned to football in 1981, playing quarterback for the semipro New Orleans Blue Knights of the Dixie Football League. He played with the Blue Knights for six seasons while working the docks of New Orleans, loading and unloading barges. In
1983, Gilliam attempted a comeback to pro football in the new
United States Football League, but was cut by the
Denver Gold, then picked up by the
Washington Federals. and retired from the sport for good. In 1986, Joe Gilliam was inducted into the American Football Association's Semi Pro Football Hall of Fame. ==Personal life and death==