Ruling party candidate Malam Bacai Sanha is one of three front-runners
Polls have closed in Guinea-Bissau where a new leader is being elected four months after soldiers killed President Joao Bernardo Vieira.
Eleven candidates were contesting the election in the impoverished West African nation.
Front-runners were Malam Bacai Sanha of the ruling party, and former presidents Henrique Rosa and Kumba Yala.
President Vieira was killed in March in apparent revenge for the death of the head of the army in a bomb blast.
He had ruled Guinea Bissau for a total of 23 years, from 1980-1999 and from 2005-2009.
About 600,000 of the country's 1.3 million residents were eligible to vote in the polls. A second round of polling could be held if there is no outright winner.
While no official figures were released, the head of the EU observer mission said voter turnout appeared less than during the legislative election in December, when 82% participated.
"Rain played a role but it is not the only factor," said Johan Van Hecke.
He added that the EU had posted observers to 80 out of the 2,700 polling stations and had received no reports of incidents or complaints during the vote.
Malam Bacai Sanha, who served as interim president from 1999-2000, was the ruling party candidate.
He faced his biggest challenges from opposition leader and former President Kumba Yala, who was overthrown in a 2003 coup, and from Henrique Rosa, who served as interim president from 2003-2005.
All three leading candidates have promised to bring peace and stability to the nation.
They have also promised to tackle the drug trade in Guinea-Bissau, which has become a transit point for gangs shipping cocaine from South America to Europe.