Tobacco use on the silver screen peaked in 2005 and has been on the decline ever since. Movies released last year showed about half the number of smoking incidents than films four years earlier.
The study released Thursday looked at tobacco use in popular films from 1991 to 2009.
Last year, about half of the 145 movies in the study didn't show any smoking at all. For films aimed at children or teens, the percentage was even higher at 61 percent. However, slightly more than half of the movies rated PG-13 did show tobacco use.
The report is in a publication from the Centers for Disease Control and Prevention in Atlanta.