Polling booths in Lithuania opened at 7am (0400 GMT) on Sunday for the second round of presidential polls as well as the European parliament elections.
Around 2.5 million people were registered to vote in the elections, which end at 8pm. They will decide the successor to incumbent president Dalia Grybauskaite, who in 2009 became the first woman to lead the Baltic country.
No clear favorite has emerged in the run-off between former finance minister Ingrida Simonyte and economist Gitanas Nauseda as pre-poll surveys have not been allowed since the first round of elections on May 12.
Simonyte, 44, led the first round with 31.21 percent of the votes, slightly ahead of 55-year-old Nauseda who received 30.93 percent of the votes.
The Lithuanian Farmers and Greens Union, party of the incumbent prime minister Saulius Skvernelis - who was himself a presidential candidate but failed to make it to the run-off - has urged people to vote for Nauseda.
Both are veteran economists, but independent candidate Nauseda focused his campaign more on social aspects, while Simonyte identified with the priorities of her party, the center-right Homeland Union.
The Lithuanian presidential post has limited executive powers, but carries the authority to appoint the prime minister, propose bills and play an important role in foreign policy.
Along with the presidential run-off, Lithuanians are also electing their 11 representatives in the European Parliament, with 16 parties in the fray.
Estonia, the smallest of the Baltic states, is also set to hold European elections on Sunday, with 6 seats in the European parliament, while neighboring Latvia voted for its 8 seats on Saturday.