The announcement, made in a government filing Friday, sent Hertz shares down nearly 10 percent in morning trading.
The Park Ridge, New Jersey, company said it will restate financial statements from 2011 and will correct and possibly restate statements from 2012 and 2013.
"Financial statements for 2011 should no longer be relied upon," the company said in the filing. "It will take time to complete this process, and previously reported information is likely to change."
The errors were related to the depreciation of some of its non-fleet assets and an allowance for doubtful accounts in Brazil, among other items, it said.
Hertz is also delaying the release of its first-quarter earnings report again. In May, it pushed the release date to June 9. Now, the company expects to release it when it amends its past full-year results. Its first-quarter results will be hurt by costs associated with the accounting review, the company said.
It said it is implementing new procedures to strengthen its accounting and finance departments.
Shares of Hertz fell $2.60, or 8.5 percent, to $27.89 in morning trading Friday. Its shares had risen 6.5 percent so far this year through Thursday's close.