Shoulder instability is a common clinical problem that negatively impacts patients’ quality of life. Humeral Avulsion of the Glenohumeral Ligament (HAGL) lesions are an underdiagnosed and undertreated cause of shoulder instability. HAGL lesions are typically caused by a traumatic event, and taking detailed history is crucial, including injury mechanism and arm positioning. A thorough physical exam is necessary, considering HAGL lesions often coexist with other shoulder problems. Complete shoulder x-rays and MRI are essential for evaluation. HAGL lesions vary in type and severity, categorized by the West Point system. Nonoperative management is initial, but surgical intervention is often needed. Surgical options include arthroscopic and mini-open techniques, both showing better outcomes than nonoperative methods. Future research could involve a randomized control trial comparing mini-open to arthroscopic repair for HAGL lesions.