He unsuccessfully ran for the parliamentary seat for Komárom-Esztergom County 5th Constituency in the elections in 1990. He became Deputy Chairman of the Independent Smallholders Party in July 1994. He was elected to a member of the National Assembly during the 1994 elections from the party's National List. He was appointed Deputy Chairman of the Committee on Agriculture.
After the 1998 elections, Gyimóthy became a deputy speaker of the parliament. He frequently used yellow and red cards to rebuke MPs. In 2000, former Prime MinisterGyula Horn referred to FKGP leader Torgyán as "Pubi", which is why Gyimóthy called him to order. Horn answered: "This is offensive? Do not be silly, Géza!" This moment became a political anecdote in Hungary.
In 2001-2002 the FKGP split into two parts and Gyimóthy's relation with the Party Chairman decayed. He was a candidate for the position of Minister of Agriculture, when Torgyán resigned; however, he was expelled from the party by Torgyán. As a result, Gyimóthy also lost his role as the legislative deputy speaker. After the failure of the 2002 Hungarian parliamentary election for the FKGP, he retired from politics.
