Established a private law practice in Little Rock from 1968-1970. Served as Prosecuting Attorney for the Sixth Judicial District of Arkansas from 1971-1972. He was appointed to the Arkansas Criminal Code Revision Commission and served from 1973-1975. Tucker was elected Arkansas Attorney General and served from 1973-1977. He was a delegate to the Democratic National Convention in 1972.
Tucker was elected as a Democrat to the Ninety-fifth Congress and served from (3 January 1977 - 3 January 1979). In 1978 Tucker gave up his seat in the House to wage an unsuccessful campaign for the United States Senate.
Tucker was convicted of federal fraud charges in 1996 as part of the Whitewater scandal investigation. Arkansas law prohibits convicted felons from serving as Governor and as a consequence Tucker resigned. As his successor, Mike Huckabee, was preparing to be sworn in Tucker rescinded his resignation on the grounds that his appeals were not complete and that the state constitution was vague about his status as a convicted felon. These events threw the state into a constitutional crisis for a short time. Tucker reinstated his resignation shortly thereafter and left office.
Soon after leaving office Tucker experienced serious health problems from chronic liver disease and nearly died in 1994 from serious gastro-intestinal bleeding. He was sentenced to four years probation due in part to the serious threat to his health posed by his ailment. In 1997 Tucker received a liver transplant at the Mayo Clinic.
Jim Guy Tucker is currently a resident of Little Rock, Arkansas and in recent years has avoided the media spotlight.