The femur is the largest and strongest bone in the human body, and great force is necessary to fracture it. In adults, the most common cause of femur fracture is motor vehicle accidents. In children, abuse is often the cause. And in the elderly, femur fractures most often occur from falling. Radiography is the gold standard for diagnostic imaging of femurs, but diagnosis can be complicated with nondisplaced or occult fractures. Particularly in the emergency setting, modalities such as magnetic resonance imaging or computed tomography may be necessary. Effective treatment of femur fractures is needed to restore homeostatic function and prevent complications.