With increasing participation and intensity of training in youth sports in the United States, the incidence of sports-related injuries is increasing, and the types of injuries are shifting. In this article, the authors review sports injuries of the lower extremity, including both acute and overuse injuries, that are common in or specific to the pediatric population. Common traumatic injuries that occur in individuals of all ages (eg, tears of the acetabular labrum and anterior cruciate ligament) are not addressed, although these occur routinely in pediatric sports. However, some injuries that occur almost exclusively in high-level athletes (eg, athletic pubalgia) are reviewed to increase awareness and understanding of these entities among pediatric radiologists who may not be familiar with them and thus may not look for them. Injuries are described according to their location (ie, hip, knee, or foot and ankle) and pathologic process (eg, apophysitis, osteochondritis dissecans). Examples of abnormalities and normal variants of the anatomy that are often misdiagnosed are provided. The injuries reviewed represent a common and growing subset of pathologic processes about which all pediatric and musculoskeletal radiologists should be knowledgeable. Understanding physeal injury is especially important because missed diagnoses can lead to premature physeal closure and osteoarthritis. RSNA, 2016.