Thompson was the first quarterback selected in the
1979 NFL draft, taken third overall by the
Cincinnati Bengals. At the time, the team had 30 year old
Ken Anderson as their starter, who had just finished his seventh season as the starter for a team that went 4–8. Team president and founder
Paul Brown felt the need to draft a successor to Anderson to help the team despite projections that saw the
New York Giants pick him at the seventh spot. Thompson was tabbed as the backup for Anderson, who started the first three weeks of the season. Thompson was put in mop-up duty for the second game before throwing twenty passes in the second game in a 20–14 loss to the New England Patriots; on the run in both games, he had a touchdown in each one. In week four against the Houston Oilers, he was tabbed to start. He went 11-of-21 for 181 yards with an interception while being sacked seven times and running for zero yards in a 30–27 loss. He did not start another game that year, but he did make appearances in five subsequent games in relief. In total, he threw for one touchdown and five interceptions while running for five touchdowns. The following year saw
Anthony Munoz drafted to provide support in the tackle position while Thompson and Anderson vied for playing time under new head coach
Forrest Gregg. On opening day of 1980, Thompson was tabbed as the starter against the Tampa Bay Buccaneers. The game did not go well, as he completed 6-of-21 for 47 yards with a touchdown and an interception in a miserable 17–12 loss. He was tabbed to come in for Anderson in the following two games, which included going 9-for-18 with 122 yards and two touchdowns that saw Cincinnati beat Pittsburgh 30–28. He was then tasked to start the following week against Houston and went 14-of-24 for 134 yards with a touchdown and an interception, but a last-minute drive to tie fell short in a 13–10 loss. He played sparingly for the next eleven weeks before being tabbed to start the final two games of the year against Chicago and Cleveland. In total, he threw for 1,324 yards while running for 84 that saw eleven touchdown passes to twelve interceptions while the Bengals as a whole won just six games.
1981 was a turning point, but not for Thompson. Anderson threw three interceptions in the first half of the opening game against the
Seattle Seahawks, but Thompson had suffered a sprained ankle injury in the preseason, which meant that Gregg went to
Turk Schonert in relief that saw a wild comeback win. As related by Thompson later, “I was in a quarterback meeting talking to Kenny and I remember him looking at me and saying, ‘I need to be the starter. He was resolved. I said, ‘Why don't you go talk to Forrest and be done with it?’ He did, then went into that New York game and had a great game and we were off and running. I got to witness his ‘Phoenix’ moment. I have nothing but respect for that.” With his job on the line, Anderson proceeded to have a standout season that saw them go all the way to
Super Bowl season while Thompson threw just 49 passes in mopup duty. His final pass as a Bengal was in the AFC Championship Game, dubbed as the "
Freezer Bowl" due to the subzero temperatures that saw him come in and complete a 14-yard pass when Anderson was checked up for a time. Thompson went to the
Tampa Bay Buccaneers in
1983 and was the
starter, but he was replaced in the
following year by
Steve DeBerg. In 2008,
ESPN ranked Thompson no. 26 among the 50 worst NFL draft busts. ==NFL career statistics==