Purpose: Physical activity is associated with reduced risk and progression of breast cancer, and exercise can improve physical function, quality of life, and fatigue in cancer survivors. Evidence on factors associated with cancer survivors’ adherence to physical activity guidelines from the American Cancer Society and the U.S. Department of Health and Human Services is mixed. This study seeks to help fill this gap in knowledge by examining correlates with physical activity among breast cancer survivors. Methods: Overweight or obese breast cancer survivors (N = 692) were examined at enrollment into a weight loss intervention study. Questionnaires and medical record review ascertained data on education, race, ethnicity, menopausal status, physical activity, and medical history. Measures of anthropometrics and fitness level were conducted. Regression analysis examined associations between physical activity and demographic, clinical, and lifestyle factors. Results: Overall, 23 % of women met current guidelines. Multivariate analysis revealed that body mass index (p = 0.03), emergency room visits in the past year (p = 0.04), and number of comorbidities (p = 0.02) were associated with less physical activity. Geographic region also was associated with level of physical activity (p = 0.02), with women in Alabama reporting significantly less activity than those in other participating regions. Conclusions: The majority of overweight/obese breast cancer survivors did not meet physical activity recommendations. Physical activity levels were associated with degree of adiposity, geographic location, and number of comorbidities. The majority of overweight breast cancer survivors should be encouraged to increase their level of physical activity. Individualizing exercise prescriptions according to medical comorbidities may improve adherence.