There were long queues to many polling stations during the day and although voting officially ended in some areas at 16:00 local time, by law polling stations could not shut until the last person in line had voted.
A strict law in Venezuela prevents exit polls being broadcast or published in any way until the electoral commission has sorted through over half the ballots and made public its initial findings on how the vote is going.
Security sources reported no serious incidents during voting. Extra forces had been deployed in case the election campaign had spilled over into violence.
There had been rumours of fraud by some in the Rosales' camp but election officials reported no irregularities.
Chavez supporters were upbeat as they
turned out to vote
Highlighting the high voter turnout Chavez earlier said he expected "democratic results".
Despite his consistent lead in the polls, the campaign has highlighted divisions in Venezuela and extremes of view were found among many waiting voters.
In the neighbourhood of San Bernadino, where middle-class streets surround a slum Margarita Budik, a retiree and Rosales supporter called the election the most important in the 50 years since she first voted.
The 68-year-old said: "This election will decide whether one can live here, or whether we have communism."
Storekeeper Julio Cesar Perez, 59, awaited his turn near an anti-imperialist mural displaying a caricature of Uncle Sam and the words, "the fatherland cannot be sold".
Wearing a bright red shirt in support of Chavez, he said: "This shirt says it all."
Chavez had earlier accused Washington of seeking to sow discord in Venezuela, and denounced his electoral rival as a lackey of the "US empire".
Chavez, 52, has pledged to start a new socialist era if re-elected.
Rosales claims Chavez is wasting the
country's oil wealth
Rosales, who has managed to unify a previously discordant Venezuelan opposition, says that Chavez is seeking to turn Venezuela into a communist state and called him "a puppet seated on Castro's lap".
Sixteen million people were eligible to vote in the presidential election, including 17,000 who were registered to turn out and vote in Miami, Florida.
The vote ended a busy electoral year in the Latin American region which has seen five left-wing or left-leaning presidents elected into office.