Fatigue fractures of the femoral neck are potentially disabling injuries if the diagnosis is missed or delayed and proper treatment is not provided. Previously considered primarily an injury of military personnel, femoral-neck fatigue fractures are becoming increasingly more common among nonmilitary athletes. The pathogenesis of this condition is multifactorial. Ultimately, fracture is thought to be caused by repetitive submaximal stresses that occur with a frequency that exceeds the adaptive ability of the bone. The clinical hallmark of a femoral-neck fatigue fracture in an impact-loading athlete is nonspecific, activity-related hip pain that is relieved by rest. Plain radiographs obtained initially are often negative. Radionuclide imaging is useful but not specific. Magnetic resonance imaging has demonstrated better specificity, sensitivity, and accuracy than are available with other modalities in the diagnosis of this injury. Treatment of compression-side injuries is generally conservative. Treatment of tension-side injuries remains controversial. The authors recommend aggressive treatment of tension-side injuries to prevent the potentially catastrophic sequelae of displacement, which include osteonecrosis, malunion, and coxarthrosis.