Many voters in the state's most populous cities and counties were standing in long lines well after polls closed Tuesday night.
Those in line when the polls closed at 7 p.m. are allowed to vote. Election officials say it could take until 10 p.m. or later for the last voters in the state to cast ballots.
Virginia State Board of Elections Secretary Donald Palmer said there were long lines in Richmond, Arlington, Virginia Beach, Roanoke and Hampton, along with Fairfax County.
"It could go as late as 11 p.m. with the last of the localities where we receive results because some will go at least two or three hours past the deadline, which was seven, to get their results to the locality and then uploaded to our statewide database," Palmer said.
The board agreed after the polls closed to delay releasing results because it wanted to ensure voters aren't unduly influenced by preliminary results.
The board says it consulted with officials from the Republican and Democratic parties on the move.
Palmer said there were several things that could have contributed to the long lines aside from a high interest in the election. Some polling sites didn't have enough of the computers used to verify voter identity to handle the high demand. Palmer said there were also people taking longer than usual to vote because there were two constitutional amendments on the ballot that many people found confusing.
Tony Guiffre, secretary of the Prince William County elections board, said several precincts had two-hour lines at poll closing, and one precinct might not be finished voting until 10 p.m.
"The people in the lines are the most polite, patient people," he said.
At one point Tuesday morning, he said, one precinct had a 4 1/2 hour line.