"I am not going to run," he said. "Governing is totally different than campaigning."
The 73-year-old lawmaker who retired as a heart surgeon said he intended to endorse his Republican primary rival Dick Jones in the November elections.
Gandhi had defeated Jones in the 2012 Republican primary.
"We became good friends after our election," Gandhi said. "I'll definitely endorse him."
He said he experienced personal frustration with a legislative process requiring members to make snap decisions on substantive policy issues, Topeka Capital Journal reported.