The opposition-dominated parliament voted for Basescu's suspension on grounds that he abused his powers.
Bogdan Olteanu, the speaker of the Chamber of Deputies, or lower house, said the measure was passed with a large majority -- by both houses of parliament -- at the end of a heated debate, with 322 voting for, 108 against, and 10 abstentions.
The suspension opens the way for a national referendum on Basescu's impeachment within 30 days.
The suspension was proposed by the former communist opposition Social Democrats (PSD). PSD leader Mircea Geoana said after the vote that the president was punished for violating the constitution.
Basescu "has been given a very serious warning by the Romanian parliament. Nobody, regardless of who he is, has the right to play with the Constitution of Romania," Geoana said.
However, the Constitutional Court has already ruled that the charges against Basescu, which include fomenting political instability, putting pressure on the judiciary, and interfering in favor of interest groups, are groundless.
The court's decision prompted the PSD to accuse Basescu on April 18 of blackmailing Constitutional Court judges to clear him.
Political Crisis Grows
Although the former communist opposition initiated the suspension procedure, it enjoyed the unlikely support of the governing Liberal Party (PNL).
For months, Basescu has been locked in a bitter conflict with both his former PNL allies and the PSD.
The PNL has repeatedly accused Basescu of interference in the government's business, while the former communists, grouped in several parties, have been uneasy about the president's drive against corruption.
Most of all, the crisis has been perceived by the Romanian public as a personal dispute between Basescu and Prime Minister Calin Popescu Tariceanu.
Tariceanu, who is also the PNL leader, earlier this month fired all ministers belonging to Basescu's center-left Democratic Party (PD), and formed a minority government with the ethnic Hungarian UDMR party. The government is supported in parliament by the PSD.
New Presidential Election?
The straight-talking Basescu, Romania's most popular politician, earlier vowed to resign "within five minutes" if suspended, and run for a new term in an early presidential election.
Tariceanu today urged Basescu to honor his pledge "to resign and stop any institutional contact with the presidency and with the institutions with which the presidency has strong ties. Romania cannot afford to have, besides an acting president, a second, shadow president."
Under the constitution, either the Senate speaker or the speaker of the Chamber of Deputies can be named acting president.
Some say political instability has already dented Romania's chances for reaping quick benefits from its new EU membership.
Basescu has so far declined to comment on the parliament vote.
However, reports from Bucharest say Basescu's supporters are gathering in the city center to protest against his suspension. It is unclear whether Basescu, who still enjoys huge popularity, will make a personal appearance at the rally.
(RFE/RL's Romania-Moldova Service contributed to this report)