The international community is hailing Afghanistan's presidential election as a triumph of democracy over violence.
Millions of Afghans went out to vote for a new president despite Taliban threats.
At least two suicide bombs have been reported, but the major attacks that had been feared did not materialize.
It may be several weeks before a winner is announced, but the U.S.-based National Democratic Institute said overwhelming turnout provided the credibility needed for the electoral process.
"The remarkable turnout along with the significant participation of Afghan election monitors, political parties, women, young people and others bodes well for the credibility of the electoral process," the group said in a statement.
The winner needs to secure more than 50 percent of the votes or there will be a run-off election in May.