Sinding-Larsen-Johansson (SLJ) syndrome is a type of osteochondrosis of the distal pole of the patella most often caused by repeated microtrauma. Here, we describe the case of a professional athlete with painful SLJ syndrome treated arthroscopically. A 29-year-old male professional handball player presented with anterior knee pain that persisted after 4 months of an eccentric rehabilitation protocol and platelet-rich plasma injections. Despite this conservative treatment, the patient could not participate in his sport. The SLJ lesion was excised arthroscopically, which led to complete disappearance of symptoms and return to competitive sports after 5 months.