The CNN/ORC International poll, conducted Wednesday and Thursday -- after the second presidential debate -- found 49 percent of likely voters in Florida said they preferred Romney while 48 percent chose Obama.
CNN Polling Director Keating Holland said Romney had a wide advantage among older and higher-income voters while Obama led comfortably among younger and less affluent voters.
Holland said Obama holds a narrow lead -- 49 percent to 47 percent -- among women voters, while Romney leads 50-46 among men.
"This suggests that in Florida women are voting more on the basis of pocketbook concerns and issues that split young and old throughout the country," adds Holland.
The poll found the two nominees are tied among independent voters and suburban voters.
The ORC International telephone survey of 1,030 adults, including 922 registered voters and 681 likely voters, has a sampling error for likely voters of 4 percentage points.