Heterotopic ossification (HO), a well-known sequela of trauma, burns, head injury, and certain congenital or acquired metabolic conditions, has a predilection for the hip and the elbow. This disease has uncommonly been found after elective open shoulder surgery but extremely seldom after minimally invasive surgery. In our search of the peer-reviewed literature, we found no reports of HO after arthroscopic rotator cuff repair. The clinical importance of heterotopic bone after shoulder surgery remains unclear because of inconsistent definitions, varying correlations of symptom severity and radiographic findings, and lack of treatment efficacy data. Here we report a case of severely symptomatic HO after arthroscopic rotator cuff repair - successfully treated with excision of the heterotopic bone, interval release, and manipulation.