Ohio elections officials say no early problems were reported as polls open in the state, some to light voter turnout.
Mitt Romney and Rick Santorum devoted most of their campaigning to the state in the last days before the 10-state primary voting, Romney looking for a decisive victory while Santorum hoped to regain momentum in his chase. They are virtually tied in some polls.
Former House Speaker Newt Gingrich also is hoping to pick up some delegates, while banking his comeback hopes on winning Georgia.
Ohio primary voters have plenty of other choices to make, including an unusual match of two Democratic U.S. House members pushed together in congressional redistricting.
There are also primaries for other House race, the Senate, state legislature and Ohio Supreme Court.
There are also local issues voters will need to decide, and you can get information on all those at your County Board of Elections websites. Polls opened up at 6:30am and will close tonight at 7:30. Voters will need some form of identification, such as a driver's license, state pay-stub or utility bill.