Polls opened at 7 a.m. and will remain open until 7 p.m.
The recall drama has already drawn a large voter turnout, with 59,000 people casting their ballots during early voting and another 68,000 filing by absentee.
Billionaire auto magnate Norman Braman spearheaded the effort to oust both Mayor Alvarez and County Commissioner Natacha Seijas last year after Alvarez pushed a property tax increase and salary raise for many county employees.
"The defining issue really is the type of government that the citizens of this community are looking for," Braman said. "It's about empowering the people of this community to take it back from the politicians who have been running it, and running it in a way that I think endangers the fiscal future of our community."
Alvarez has said he has no regrets over his recommended budget, and that it was necessary in order to maintain vital services like fire and police. He also says Braman is angry over losing an effort to block the county from funding a new $600 million stadium for the Florida Marlins baseball team.
At Alvarez's urging, the county commission approved it.
A recent survey by firm Bendixen & Amandi showed that 67 percent of likely voters planned to recall Alvarez while 60 percent favor Seijas' ouster.