Police say Smith and his wife, Racquel, had gotten into an argument just after 2 a.m. Saturday while leaving a nightclub.
Cpl. Paul Mouton says in a news release that officers on patrol saw the argument escalate and then saw Smith grab the woman's hair. Mouton says the woman's injuries were minor.
Smith was booked with domestic abuse and simple battery. He's free on $1,000 bond.
In a statement released Tuesday by the Saints, Smith says what happened was "not a domestic issue" and his wife was not injured as reported. He says he's confident "that the legal process will bear this out."
Smith, the Saints' first-round pick in 2004, was a Pro Bowl selection in 2006.