Osgood-Schlatter disease is a traction apophysitis of the tibial insertion of the patellar tendon. It consists one of the most common causes of knee pain in adolescents and usually presents in young males and it is considered a self-limiting condition. Although the symptoms disappear after the closure of the growth plate in most cases, in some patients they may persist. A variety of conservative treatments are used in most cases, however surgical intervention can be successful for patients who have intolerable symptoms. Most surgical options of the Osgood-Schlatter disease include open procedures, while arthroscopic or direct bursoscopic excision has been reported. We believe that the arthroscopic removal of an unresolved Osgood-Schlatter might be the most appropriate treatment for this condition, and we present a case of a male patient with an ununited ossicle due to an Osgood-Schlatter lesion, which was removed arthroscopically using a multidirectional arthroscope and a motorized semi-hooded barrel burr.