BACKGROUND: Although patients with coronary artery disease can benefit from adequate physical activity, low physical activity levels have been reported among these patients. Gender-based disparities might contribute to variations in physical activity. However, knowledge regarding gender differences in factors associated with physical activity among patients with coronary artery disease is limited. OBJECTIVE: This study aimed to examine gender differences in factors associated with physical activity in Taiwanese patients with coronary artery disease. METHODS: A cross-sectional design was used. A convenience sample of 215 patients with coronary artery disease was recruited from 1 medical center in northern Taiwan. Participants were interviewed using structured questionnaires to obtain information regarding their demographics, physical conditions, physical activity, self-efficacy, social support, and community exercise environment. RESULTS: Only 17.8% of male patients and 20% of female patients reported performing the recommended physical activity level. Men performed more vigorous and work-related activities, whereas women engaged in more household activities. In both genders, physical activity was significantly associated with age, disease symptoms, social support, self-efficacy, and environmental appraisal. Self-efficacy and age were significantly associated with physical activity in the linear regression analysis. Among male patients, physical activity was also related to work status, angina, comorbidity, medication, and hospitalizations, whereas disease duration was associated with physical activity among female patients. CONCLUSION: Patients of both genders reported low levels of physical activity. Nurses should recognize gender differences in factors associated with physical activity in patients with coronary artery disease and develop individualized physical activity programs to improve patients' physical activity.