Peer review has expired on this program. It is the viewer’s responsibility to determine the educational value of this historical content.Peer review has expired on this program. It is the viewer’s responsibility to determine the educational value of this historical content.Humeral avulsion of the glenohumeral ligament (HAGL) is a rare, but increasingly recognized, cause of recurrent shoulder instability in young patients. The HAGL lesions are the result of acute traumatic glenohumeral subluxation or dislocation, usually in the setting of combined hyperabduction and external rotation. Anterior avulsion of the inferior glenohumeral ligament is the most common lesion. However, posterior lesions (reverse HAGL) can also occur, and they are a cause of recurrent posterior instability. The HAGL lesion is commonly associated with other shoulder pathology, and it may therefore be easily overlooked. Early diagnosis is critical to preventing long-term morbidity. Careful history and physical exam, as well as MRI aided by intra-articular contrast, provide the diagnosis. Most untreated HAGL lesions cause recurrent instability and require surgical repair. According to the literature, surgeons have achieved excellent results using arthroscopic, open, and mini-open/subscapularis-sparing approaches. The purpose of this video is to provide a comprehensive review of the HAGL lesion and its treatment.