ABSTRACT Physical activity may contribute to important health and well-being outcomes among older adults. Efforts to understand determinants of physical activity are necessary to plan effective interventions. The theory of planned behavior has been successfully applied to a variety of health behaviors. Previous research using the theory of planned behavior has not addressed beliefs about overall physical activity among communitydwelling older women. Qualitative interviews were conducted with 30 older women to identify behavioral beliefs, perceived control beliefs, and normative beliefs, which influence physical activity decisions. Content analyses of responses revealed three major themes: social influences on physical activity, psychosocial benefits of activity, and joint problems and fatigue as factors that interfere with activity. These findings about physical activity were compared with published findings about episodic exercise among 30 similar women who took part in an episodic exercise study. The result was the discovery that the women in this study talked about physical activity as embedded in their social lives while the women in the episodic exercise study viewed exercise as separate from their daily lives. These findings of beliefs about overall physical activity suggest a social model may be useful in planning public health interventions to increase activity among older women.