Rolandas Paksas was impeached four years ago
Lithuania's main conservative opposition party has won most votes in the first round of general elections.
But no clear winner has emerged and another coalition is in prospect.
The Homeland Union took about 18% of the vote, while the governing Social Democrats were pushed into fourth by two rival populist parties.
The National Revival Party, led by a former talent show host, and impeached ex-President Rolandas Paksas' Order and Justice won more than 27% between them.
Final results are not due until the second round vote, set for 26 October.
Tough coalition talks lie ahead. Correspondents say Order and Justice could form a populist partnership with Russian-born millionaire Viktor Uspaskich's Labour party.
Mr Uspaskich - known as Mr Gherkin because of his pickles business - is battling corruption allegations and is barred from leaving Lithuania.
Lithuanians also voted on closing a Russian nuclear plant
Ex-stunt pilot Mr Paksas was the first European head of state to be removed by impeachment. He quit four years ago amid corruption allegations, which he has always denied.
Although still banned from holding public office, analysts say he could wield huge influence behind the scenes.
The Social Democrats' four partners in the coalition government failed to break the 5% barrier to remain in parliament, according to the exit poll.
In power since 2001, the Social Democrats were in trouble due to the failing economy of the ex-Soviet state, which joined the European Union in 2004.
Turnout among Lithuania's 2.6 million registered voters was 46%, down one point from four years ago, electoral commission figures showed.
Voters also took part in a non-binding referendum on whether to shut a Chernobyl-style nuclear plant, but figures suggested the plebiscite could be invalid due to the low turnout.
The European Union wants Lithuania to shut the plant as planned at the end of 2009.
However, it provides 70% of Lithuania's electricity, and many voters do not want to increase their country's dependency on Russia.