In the 2004 presidential election, Moroz was nominated by the Socialist Party which he has chaired since 1991. He won third place with 5.81% of the vote. As a longtime leader of anti-Kuchma forces, Moroz quickly announced his support for Viktor Yushchenko's presidential bid against Kuchma's Prime Minister Viktor Yanukovich, thus making Yushchenko the favourite to win in round two. That Yushchenko did not win despite this endorsement was used to argue that there was election fraud in the run-off. Moroz supported the subsequent Orange Revolution, the mass protests that eventually led to the annulment of the vote results and to a revote won by Yushchenko. The support of the Ukrainian Socialists he brought to Yushchenko's campaign was important to widen Yushchenko's appeal to voters. Similarly, the votes of Moroz's Socialist Party faction in Verkhovna Rada (parliament) were crucial for passing several important resolutions during the Orange Revolution, particularly the non-confidence vote in the Kuchma–Yanukovych government involved in election fraud scandal.