Lohan's vehicle clipped a 34-year-old man in an alley, around 2:30am (local time), police told Reuters, and the man later went to a nearby hospital saying he had an injured knee.
The 26-year-old actress, who has been in and out of court, rehab and prison since a 2007 drunk driving arrest in Los Angeles, was arrested for leaving the scene of an accident. Police arrested her as she left the Dream hotel in lower Manhattan.
She was charged with a misdemeanor and released, the New York police department's Office of Public Information said.
Lohan's spokesman in Los Angeles said he believed the claims would not be proved.
"While some of the facts are still being gathered, it appears that this is much ado about nothing. We are confident this matter will be cleared up in the coming weeks and the claims being made against Lindsay will be proven untrue," spokesman Steve Honig said in a statement.
Celebrity website TMZ.com, quoting sources at the hotel, said surveillance video of the incident made it hard to tell whether Lohan's car made contact with the pedestrian or, if it did, how hard.
The New York Daily News identified the man as Jose Rodriguez, a cook who was leaving his workplace, the adjacent Maritime hotel, when the incident occurred.
A Los Angeles judge released Lohan from formal probation in March, but she was instructed to obey all laws until 2014. A conviction in the New York case could trigger a violation of those conditions.
Lohan, who rose to fame as a child star in the 1990s, has been trying to make a comeback after her once promising movie career was derailed. She stars as screen legend Elizabeth Taylor in a Lifetime TV movie, "Liz & Dick," due to air in November.
