ABSTRACT: Context: Obesity is epidemic in the United States, but information on this trend by type of rural locale is limited. Purpose: To estimate the prevalence of and recent trends in obesity among US adults residing in rural locations. Methods: Analysis of data from the Behavioral Risk Factor Surveillance System (BRFSS) for the years 1994–1996 (n = 342,055) and 2000–2001 (n = 385,384). The main outcome measure was obesity (body mass index [BMI] ≥30), as determined by calculating BMI from respondents' self-reported height and weight. Results: In 2000–2001, the prevalence of obesity was 23.0% (95% confidence interval [CI] 22.6%-23.4%) for rural adults and 20.5% (95% CI 20.2%-20.7%) for their urban counterparts, representing increases of 4.8% (95% CI 4.2%-5.3%) and 5.5% (95% CI 5.1%-5.9%), 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% (95% CI 29.1%-33.6) in rural counties adjacent to urban counties. The largest difference in obesity prevalence between those with a college education compared with those without a high school diploma occurred in urban areas (18.4% [95% CI 17.9%-18.9%] vs 23.5% [95% CI 22.5%-24.5%], respectively); the smallest difference occurred in small, remote rural counties (20.3% [95% CI 18.7%-21.9%] versus 22.3% [95% CI 20.7%-24.0%], respectively). Conclusions: The prevalence of obesity is higher in rural counties than in urban counties; obesity affects some residents of rural counties disproportionately.