Abstract Despite well-documented benefits of exercise, aging women remain largely sedentary. Further understanding of beliefs associated with exercise could result in more-effective public health interventions to increase exercise in this vulnerable population. This study examined the relationships between theory of planned behavior constructs and exercise behavior and exercise intention in older women. Constructs from the theory of planned behavior (behavioral beliefs, perceived control beliefs, and normative beliefs) were examined in a sample of 225 women aged 65 and older. Exercise was measured with the Baecke Physical Activity Scale. All women were interviewed, to prevent literacy and vision problems from hampering participation. Significant predictors of exercise behavior were perceived control beliefs and behavioral beliefs. Significant predictors of exercise intentions were perceived control beliefs, behavioral beliefs, and normative beliefs. Specific belief items predicting exercise behavior were that exercise is good for health and that exercise is difficult because of tiredness, as well as the lack of commitment and time. These findings provide partial support for the application of the theory of planned behavior to exercise in older women. The findings suggest that interventions should focus on increasing women's confidence that they can overcome barriers to exercise.