Greeks living abroad started casting their ballots for the general elections, a day earlier than voters living in Greece.
It is the first time ever that Greek expatriates can vote from their place of residence, based on criteria set out in a recent law.
In previous elections, Greek expatriates who wanted to participate in elections had to return to Greece to vote, Xinhua news agency reported.
A total of 22,816 expatriates registered to vote in places where they are living, according to the Interior Ministry on Saturday. They can vote at 99 polling centres located in 35 countries, as a minimum of 50 registered in an area was required to set up a polling station.
Most have registered in the UK, Germany, the US, Belgium and Cyprus, according to the Ministry.
Their ballots will be sent back in sealed bags by planes and the votes will be sorted when the polls close in Greek territory, Greek national news agency AMNA reported.
A total of 9.8 million Greeks are eligible to elect the 300 members of parliament.
All recent opinion polls indicate that the ruling conservative New Democracy (ND) party leads, with the Leftists following second and the Socialists third.
According to political analysts, due to the way the Greek electoral system works, it will be difficult for any single political party to secure a clear parliamentary majority in the first round.
If a second election round is required, it will take place at the beginning of July at the latest, the government has said. The second round would be held under new electoral rules, which provide for extra seats for the winning party.