Pruitt was a State Senator, representing Tulsa and Wagoner counties from 1998 until 2006. When U.S. Congressman Steve Largent decided not to seek reelection in Oklahoma's 1st congressional district, Pruitt ran unsuccessfully for the Republican nomination to succeed Largent against the First Lady of Oklahoma, Cathy Keating and the eventual nominee and winner, John A. Sullivan. In the 2002 election cycle, Pruitt was re-elected without opposition by his home district. Rather than seek re-election in 2006, Pruitt launched a failed campaign to receive the Republican nomination for Lieutenant Governor of Oklahoma.
He entered into private practice in Tulsa where he specialized in Constitutional Law, Contracts, Insurance Law, Labor Law, and Litigation & Appeals. After five years as an attorney, Pruitt ran for, and was elect to, the Oklahoma Senate in 1998, representing Tulsa and Wagoner counties. After only two years in the Senate, Pruitt was selected to serve as the Republican Whip from 2001 to 2003. He was then selected to serve as the Republican Assistant Floor Leader, a position he held until he left the Senate in 2006.
In 2004, Pruitt became the General Managing Partner of the Oklahoma RedHawks, Oklahoma City's Triple-A baseball club. Under his first season of leadership, the RedHawks saw a 25% increase in attendance. After two years, the team broke the all-time attendance record for minor league baseball in Oklahoma and saw a 45% increase in revenue.
Pruitt, while still a freshman legislator, sought his party's nomination to succeed Steve Largent as the Member of Congress for the First Congressional District of Oklahoma in 2001. Largent, who had resigned to spend his focus running for Governor of Oklahoma, would be replaced by special election rather than by gubernatorial appointment. Two other main candidates emerged for the job, including sitting State Representative John A. Sullivan, the eventual winner, and Cathy Keating, the wife of then Governor Frank Keating. Pruitt came in a distant third behind a surprisingly successful first place finisher in Sullivan and Keating in second place. The Keating loss prompted then Governor Frank Keating to say the voters in his hometown of Tulsa were "dumb," a remark he later recanted as being emotionally supportive of his wife.