To estimate the prevalence of and recent trends in obesity among U.S. adults residing in rural locations, the authors analyzed data from the Behavioral Risk Factor Surveillance System for 1994-1996 and 2000-2001 and found that in 2000-2001 the prevalence of obesity was 23.0% for rural adults and 20.5% for their urban counterparts, representing increases of 4.8% and 5.5%, respectively, since 1994-1996. The highest obesity prevalence occurred in rural counties in Louisiana, Mississippi, and Texas; obesity prevalence increased for rural residents in all states but Florida over the study period. African Americans had the highest obesity prevalence of any group, up to 31.4% in rural counties adjacent to urban counties.