Norway implemented a nationwide ban on indoor smoking in June 2004. This study documents the smoking patterns of Norway's restaurant and bar workers before and after the ban, to determine changes in smoking prevalence and explore which individual and environmental characteristics were related to cessation. A national sample of food service workers was surveyed by telephone or Internet immediately before the ban and at 4 and 11 months post-implementation. Results showed that between baseline measurement and 4 months post-implementation, there were significant declines in prevalence of daily smoking (-3.6% points, p