The thigh, which consists of the heavily muscled region around the femur, is vulnerable to many types of athletic injury. This review addresses the assessment, prevention, and rehabilitation of both the common thigh injuries associated with participation in sports, such as contusions and myositis ossificans traumatica, and a few relatively uncommon but diagnostically important entities that sports physicians must recognize when an athlete has pain or dysfunction attributable to the thigh. Dividing the thigh into anatomic compartments aids in both differential diagnosis and understanding of the pathomechanics that lead to injury. Rehabilitation is especially emphasized because improper selection of modalities or misuse of exercise can seriously impede or worsen recovery. Conversely, the use of appropriate rehabilitation principles and new concepts in exercise prescription can decrease morbidity and lead to rapid resumption of sports.