The literature suggests that individuals will be healthier if they live in Active Community Environments that promote exercise and activity. Two key elements of such environments are walkability and safety. Examining data from the National Health and Nutrition Examination Survey III, 1988-1994 and using a multilevel analysis, we found that individuals who live in counties that are more walkable and have lower crime rates tended to walk more and to have lower body mass indices (BMIs) than people in less walk-able and more crime-prone areas, even after controlling for a variety of individual variables related to health. Among lifelong residents of an area, lesser walk-ability and more crime were also associated with respondents reporting weight-related chronic illness and lower ratings of their own health. The effect of high crime rates was substantially stronger for women than for men, and taking this interaction into account eliminated gender differences in walking, BMI, weight-related chronic conditions, and self-reported poor health. The results suggest that to promote activity and health, planners should consider community walkability, crime prevention, and safety.