The increasing frequency of injury in young athletes over the last 2 decades reflects the increases in sports participation of children of a young age. Physical injury is an inherent risk in sports participation at any age. In general, the factors causing sports injuries can be grouped in 2 separate broad categories: extrinsic and intrinsic factors. However, the great majority of injuries which are sustained are minor and self-limiting, suggesting that children and youth sports are safe. However, a increasing number of children undergo treatment because of the effects that injuries may have on their developing bodies. A child's skeletal system shows pronounced adaptive changes to intensive sports training. Sports injuries affect both growing bone and soft tissues, and could result in damage of the growth mechanisms with subsequent life-lasting damage. Adolescents are particularly vulnerable to injuries, at least partially due to an imbalance in strength and flexibility. During growth there are significant changes in the biomechanical properties of bone. In young athletes, as bone stiffness increases and resistance to impact diminishes, sudden overload may cause bones to bow or buckle. Epiphyseal injuries occur at the epiphyseal growth plates. They are usually due to shearing and avulsion forces, although compression also plays a significant role. Given the remarkable healing potential of bone in youngsters, fractures that initially united with some deformity can completely remodel and appear totally normal in later life. As the risk of injuries sustained by young athletes can be significant, it is essential that training programmes take into account their physical and psychological immaturity, so that the growing athlete can adjust to their own body changes.