Parliament speaker Volodymyr Lytvyn initiated the voting by reading the wording of resolution 255: "Declaring invalid the results of the second round of voting in the presidential elections on 21 November, and that they were accompanied by violations of electoral law and did not fully reflect the will of the people."
Shortly afterward Lytvyn announced the results of the vote by saying: "The [resolution] has been passed."
Deputies also passed a vote of no confidence in the Central Election Commission and called on outgoing President Leonid Kuchma to nominate new members. And they voted to set up a special investigative committee to look into reported violations.
But they did not suggest a date for holding a new vote, which the opposition wants to be held on 12 December.
Outside, thousands of opposition protesters encircled the building and listened to the proceedings.
Today's votes are nonbinding. But correspondents say they are a boost to the opposition, after a week of growing street protests over an election many observers say was marred by fraud.
Thousands of opposition supporters continued protesting in the streets of Kyiv for a sixth straight day today, while in eastern Ukraine, a similar number turned out in support of Yanukovych.
Shortly before today's parliament session, the European Union said the best outcome to the crisis would be fresh elections.
The comment came from Dutch Foreign Minister Ben Bot, whose country currently holds the EU's Presidency.
That's a demand Yushchenko has been making, most recently last night, after he emerged from a meeting with Yanukovych and international mediators.
"We are sure that any deals about forming a government, any deal on sharing posts in government, any deals on political reform, will not resolve the political crisis which we face today, because this crisis has come about through falsification of elections," Yushchenko said. "That is why the answer has to come in the shape of a new vote. There is no other way."
Yesterday's meeting produced an agreement to set up a working group to pursue talks. Negotiators from both candidates' camp were to meet today.
On 29 November, Ukraine's Supreme Court begins key hearings when it considers an appeal by Yushchenko to nullify the election result.
Yanukovych cannot be inaugurated as president until the Supreme Court issues its ruling.