German MPs have voted by 496 to 90 to back the second EU/IMF bailout for Greece.
Chancellor Angela Merkel had urged them to back the deal, while conceding there was "no 100% guarantee" it would work.
Several MPs in her party opposed the deal but it was not clear if they had voted against the government.
Germany will have to pay more than any other country for the 130bn euro ($173bn; £110bn) package, agreed by eurozone states last week.
Although the Bundestag (lower house) had the power to block the bailout, it was always expected to go through because of the support of two opposition parties, the Social Democrats (SPD) and Greens.
In the event, there was a large majority in favour of the deal, with five MPs abstaining in the vote.
The BBC's Stephen Evans, in Berlin, says that despite the five-to-one majority, there is a great deal of scepticism about the bailout's effectiveness both among politicians and the wider population.
Interior Minister Hans-Peter Friedrich, from the ruling Christian Democrats' Bavarian sister party, the Christian Social Union (CSU), had earlier argued that Greece's chances of recovery would be better if it left the eurozone.
"I'm not talking about throwing Greece out, but rather about creating incentives for an exit that they can't pass up," he told Spiegel magazine on Sunday.
Under the front-page headline "Stop", Germany's mass circulation Bild newspaper made a direct appeal to parliament: "Don't keep on going the wrong way."
An opinion poll for Bild's Sunday edition suggested that 62% of those surveyed wanted MPs to vote against the package.
Mrs Merkel told the Bundestag that she was aware that people were concerned that Greece was a "hopeless case" and that the eurozone would be better off without it. But she had come to the conclusion that "the opportunities of this new package outweighed the risks".
"No-one can predict what the repercussions of a disorderly default would be for all of us and also for the people of Germany."
Under the terms of the bailout, Greece has to approve 3.2bn euros in budget cuts and has already backed a debt swap with banks and private investors to wipe out 107bn euros of debt.
For the opposition SPD, former Finance Minister Peer Steinbrueck told MPs that the government's crisis management followed a motto of "too little, too late and above all too vague".
But he said his party would support the deal as it was in Germany's economic and national interest.
Left Party leader Gregor Gysi bitterly criticised the SPD and Green decision to back the coalition government, comparing the deal secured for Greece with the Treaty of Versailles that led to major German reparations and concessions after World War I.
"Greece needs a Marshall Plan, not a Versailles Treaty," he said.
The chancellor also said that Germany was prepared to speed up the planned payment of capital into the new permanent bailout fund, the European Stability Mechanism (ESM), with 11bn euros this year and a second portion next year.
Mrs Merkel said that she was resisting pressure to increase the size of the ESM from its 500bn euro capacity when it comes into existence in July.