"If I had a choice, I would do comedy all the time," the 54-year-old actor told reporters in New York recently while promoting his big-screen police comedy "Cop Out."
"Comedy is just the most challenging thing," Willis added. "To make someone laugh is A. the most challenging thing and B. the most rewarding thing in entertainment."
Willis' co-stars Tracy Morgan and Seann William Scott, as well as his director Kevin Smith, admitted they felt compelled to try to make Willis crack up whenever they could on the set of their film.
Asked if they were successful, Willis recalled: "There are scenes where I'm just trying not to laugh. There were a lot of times that we broke and it wasn't just me. A lot of times it was the whole crew who was watching on the monitors."
"Cop Out" opened at No. 2 at the U.S. box office last weekend.