BACKGROUND: The purpose of this study was to identify and determine the influence of perceived intrinsic barriers to physical activity among mothers living in rural areas. METHODS: Mothers were identified through a study of child-parent dyads in the predominantly rural states of New Hampshire and Vermont. Using a telephone interview, we asked mothers (n=1691) about their level of physical activity and assessed eight potential barriers to physical activity. Data were analyzed using chi-square tests, t tests, and analysis of variance (ANOVA) comparisons for groups within each variable. We used multiple regression analysis to assess associations between perceived barriers to physical activity and self-reported levels of physical activity. RESULTS: Each barrier was inversely associated with physical activity. Multivariate models that included terms for all potential barriers and covariates identified three barriers associated with lower levels of physical activity: lack of self-discipline, lack of time, and lack of interest. CONCLUSIONS: Rural mothers are less likely to be physically active if they identify lack of self-discipline, time, or interest as barriers, suggesting that they have difficulty prioritizing exercise for themselves. Interventions aimed at increasing physical activity for mothers should specifically consider these barriers. One possible solution may be to support infrastructure that facilitates active living as the default option, to remove the issue of having to purposefully engage in physical activity as a separate aspect of a mother's life.