The Rada, on a 226-155 vote, defeated the bill that would have addressed the reduction of penalties for exceeding authority in Ukraine's criminal code, RIA Novosti reported.
Tymoshenko was convicted in October of exceeding her authority and sentenced to seven years in prison for signing a natural gas deal with Russia in 2009. The agreement obligated Ukraine to buy larger amounts of gas than it needs at prices higher than the country's leaders say are fair. Ukraine has tried to revise the agreement.
Western leaders have denounced the trial as a witch hunt against Tymoshenko, who ran unsuccessfully against President Viktor Yanukovych. Yanukovych has denied the claim.