Lawmakers voted 213-79 in favour of the of the new agreement, with deputies backing the coalition government of socialists and conservatives broadly following their party's line.
Earlier, the Communist Party staged nationwide protests against the deal, including a rally outside parliament.
Greece narrowly avoided default this month after sealing the loan agreement — the second in two years — with eurozone countries and the International Monetary Fund, as well as a massive debt restructuring deal with banks and other private bond holders.
"There is no other solution. If anyone has an alternative, let them come forward," Deputy Finance Minister Philippos Sachinidis told Parliament for the vote.
Prime Minister Lucas Papademos' four-month-old coalition is expected to call a general election for late April or early May.
Greece has been dependent on eurozone-IMF rescue loans since May 2010. In return for the second bailout, already depleted pensions and salaries have been further cut, while the government pledged to abolish 15,000 public sector jobs this year.