Abstract Few studies have examined whether factors predicting obligatory exercise differ by gender. 303 participants completed the Obligatory Exercise Questionnaire and the Reason for Exercise Inventory. All variables correlated significantly. However, the correlation between exercising for fitness and obligatory exercise was significantly stronger in women than men. In women, obligatory exercise was predicted by exercising to improve body tone, fitness, and to enhance mood; in men, obligatory exercise was predicted by exercising to improve body tone, enjoyment, and perceived attractiveness. Implications for treatment are discussed.