"I never thought I would have to, a decade later, stand here and say that that film of mine did no good. That to me is personally heartbreaking," Moore said Tuesday night while on the red carpet at National Board of Review Awards.
His 2002 documentary, which won an Academy Award, was inspired by the 1999 Columbine High School shootings in Colorado.
Moore says he has no interest in making a film about last month's shooting at the Sandy Hook Elementary School in Newtown, Conn., that left 20 children and six adults dead.
"No, I've made the film I wanted to make with `Bowling for Columbine.' Every word in stands true to this day,