Humeral avulsion of the inferior glenohumeral ligament complex is an unusual pathology, often implicated in traumatic shoulder instability. Traditional open techniques involve at least partial detachment of the subscapularis, and arthroscopic techniques are limited by neurovascular boundaries. The technique described here presents an anterior and posterior arthroscopic approach that can be used individually or in combination to treat different types of humeral avulsion of the inferior glenohumeral ligament lesions. The anterior approach is based on anatomic guidelines described in the literature. The posterior approach is based on the arthroscopic and cadaveric anatomic studies described by one of the authors (D.N.B.); use of the recently described axillary pouch portal (Bhatia portal) permits safe arthroscopic instrumentation access in the entire inferior glenohumeral recess and provides adequate access to the posteroinferior aspect of the humeral head. The differential mattress stitch technique ensures secure fixation of the avulsed ligaments and eliminates excessive capsular redundancy. Technical tips to avoid complications are discussed, and a detailed rehabilitation protocol is presented.