Objective To determine the relationship between presence of smoking in films and total box office receipts.

Methods Regression analysis of box office receipts as a function of film rating, production budget, year of release and presence of smoking for 1232 films released in the USA between 2002 and 2010.

Results R-rated films made, on average, 87% (95% CI 83% to 90%) of what PG-13 films of similar smoking status made and smoking films made 87% (95% CI 79% to 96%) of what comparably rated smoke-free films made. Larger budget films made more money. There was no significant effect of release year or G/PG rating compared with PG-13-rated movies.

Conclusions Because PG-13 films without smoking (median $48.6 million) already make 41% more money at the box office than R-rated movies with smoking (median $34.4 million), implementing an R rating for smoking to remove it from youth-rated films will not conflict with the economic self-interest of producer-distributors.