The vote on the measure, a prerequisite to receiving the next installment of a European bailout, took place shortly after midnight Thursday local time, CNN reported. While just over half the 300 parliamentary representatives, or 153, voted yes, 18 abstained and there were 128 votes against.
About 70,000 people demonstrated outside the Parliament Building Wednesday afternoon and evening. Protesters fought police, throwing Molotov cocktails.
There were smaller demonstrations elsewhere in the country.
Melina Grigoriadou, who works for an export company, said pay cuts and higher taxes have already cost her family about one-third of their income.
"The measures just never stop. Every time, politicians say they are going to be the last measures ... they are never the last," Grigoriadou told CNN at a demonstration in Thessaloniki, Greece's second-largest city. "There is no end in this, there's no solution. The measures are awful -- it's not austerity, it's something even worse."
Unions held a second day of strikes, disrupting public transportation and other services in the country. Some mass transit resumed Wednesday in Athens so protesters could get to Syntagma Square.
The 48-hour strike has severely affected life around Athens. Suburban rail services, buses, trolleys and ferries were not running Wednesday, while taxis were operating a rolling strike for a third day. Airlines were modifying flight schedules in anticipation of a 4-hour strike by air traffic controllers.
Pharmacies were closed, and hospitals were operating with few staff.
Members of Parliament were expected to vote around midnight Wednesday on a package of bills that set out a number of structural reforms and $17.3 billion in fiscal measures that would be put in place over the next two years.
The bills affect everything from how much public employees are paid to what products supermarkets can sell. More than 25,000 public employees could lose their jobs.