Rizzi's managers, Art 28 GmbH & Co. KG, based in Stuttgart, Germany, said in a statement on its website that the artist died peacefully at his studio in New York's SoHo district on Monday. They gave no cause of death.
Rizzi was born in Brooklyn and studied art at the University of Florida. He returned to New York in 1974 and first made his name as a street artist.
He became known for his bright, cartoon-like drawings and 3-D constructions. In 1996 Lufthansa commissioned him to decorate a jet with pastel stars, birds and travelers.
Rizzi developed a large international following, especially in Germany. Last year a school in Duisburg was named for him.