A famed but ailing Manhattan painter disappeared after bringing his sick wife to New York Hospital, only to be found hours later, authorities said today.

Ninety-year-old Joseph Stefanelli — whose modernist works have hung in the Whitney Museum — suffers from dementia and wandered off while his wife was receiving treatment for an unspecified ailment at the medical center at First Avenue near East 30th Street in Murray Hill on Sunday, police sources said.

He was found later this afternoon at the corner of 41st Street and 10th Avenue and taken to St. Luke’s-Roosevelt Hospital for observation, police said.

Stefanelli, who lives on West Street in the West Village, is best known for his abstract expressionist art. In the 1950s, he was recognized worldwide for his paintings.