Osgood-Schlatter disease is a condition that is caused by traction of the muscle-tendon unit at tibial tuberosity, which affects adolescents who exercise. The predisposing factors include rapid growth and physical activity, particularly running and jumping. Osgood- Schlatter disease causes intermittent pain, which can be aggravated by running, cycling and climbing stairs. We present the case of a young boy, soccer player, which presented for pain at the level of the tibial tuberosity. Ultrasonography showed changes at the distal part of the patellar tendon and at the tibial tuberosity, consistent with Osgood-Schlatter disease.