The spokesman for the state board that oversees elections said there have so far been no major issues.
As of Tuesday afternoon, Government Accountability Board spokesman Reid Magney said there have been occasional voting equipment malfunctions, which are being addressed. But he said those are minor issues and things have gone relatively smoothly.
He said they are hearing of long lines in some places, but nothing extraordinary.
The Government Accountability Board has predicted nearly 70 percent of eligible voters will cast a ballot in Wisconsin.
Voters lined up even before the polls opened at 7 a.m. in Wisconsin on Election Day.
More than 300 people were in line when a south side Milwaukee polling place opened Tuesday morning. About 50 were in line at a polling location in the small city of St. Francis, Wis., just southeast of Milwaukee.
Standing in 28 degree weather, lines of voters at Our Redeemer Lutheran Church on Madison's west side were the earliest to cast their ballots Tuesday.
"It's great when the poll worker comes out and says, 'Hear ye, hear ye,' and they open the poll. It's kind of exciting. It kind of calls back to the 1700s," said David Houlihan, the first voter in line at Our Redeemer Lutheran Church.
The big race is for president and the state's coveted 10 electoral votes. Wisconsin voters also will choose a new U.S. senator, a House representative and state legislators.
Wisconsin voters are dealing with a wintry mix of rain and snow. An inch or more of snow is forecast for northern Wisconsin, with cold rain to the south.