Transit sources told the New York Daily News the woman, who was described as in her 20s, was sitting on a bench at the Brooklyn Bridge-City Hall station at about 9:30 a.m. Monday when the rodent ran up and bit into the flesh of her foot.
"She was pretty frantic and upset," one transit worker said. "You could actually see the bite."
Authorities said the woman was treated at New York Downtown Hospital and released.
Officials with Transport Workers Union Local 100 said rats are becoming more common at stations because of infrequent garbage collection and poor seals on trash storage rooms.
City transport officials declined to comment, the Daily News said.