The newspaper said it was initially told Lewis, 86, was treated and released at a hospital Tuesday night shortly after he fell ill while preparing to present Tom Cruise with a Friars Club award.
"I just received word that Jerry Lewis will spend a second night in the hospital. He is doing well and expected now to be released on Thursday," a Friars Club representative told the Post Wednesday night.
Lewis' publicist Candi Cazau told the newspaper he was "kept overnight as a precaution."
"He gets wrapped up and engrossed in his work, and he forgets to eat. He is diabetic, and it's important for him to keep those [blood sugar] levels up. He was feeling dizzy, and since he was not in Las Vegas where his doctors are, they did take him to the hospital as a precautionary measure. He is feeling great and is anxious to get back up and back to work," she said.