The present review of epidemiologic studies of physical activity and genitourinary cancers (prostate, bladder, renal cell, and testicular cancers) suggests a weak inverse relation of physical activity to risk of prostate and renal cell cancer, with average risk decreases of less than 10% comparing high versus low levels of physical activity. For prostate cancer, studies that assessed activity intensity or those that considered fatal prostate cancer as a study endpoint produced the strongest inverse association. For renal cell cancer, the inverse relation with physical activity was more apparent among women than men, among normal weight than overweight or obese individuals, and among older than younger individuals. In contrast to prostate and renal cell cancer, available data show that physical activity is not associated with bladder or testicular cancer. Future research should include improvements in self-reported activity measures and incorporation of objective assessments of physical activity over the life course in order to more precisely characterize types, parameters, and timing of physical activity in relation to genitourinary cancers. Also, data are lacking regarding whether fitness potentially influences genitourinary cancer risk. The relation of physical activity and fitness to genitourinary cancer prognosis and survival requires specific attention. Mechanistic research should identify the underlying biologic pathways potentially linking physical activity to genitourinary cancers.