Abstract: Tears in the gluteus medius and minimus tendons, often misdiagnosed as trochanteric bursitis, have recently emerged as an important cause of recalcitrant greater trochanter pain syndrome. Advances in endoscopic surgery of the hip have created opportunities to better evaluate and treat pathology in the peritrochanteric compartment. We reviewed the literature on trochanteric pain syndrome and gluteus medius tendon injuries. Existing techniques for endo- scopic and open gluteus tendon repair and potential challenges in restoration of abductor function were analyzed. Partial-thickness undersurface tears of the gluteus medius were iden- tified as a common pathologic entity. Although these tears are otherwise analogous to partial- thickness tears of the rotator cuff, the lack of arthroscopic access to the deep side of the gluteus medius tendon represents a unique technical challenge. To address the difficulty in visualizing and thus repairing undersurface tears of the gluteus medius, a novel endoscopic trans-tendinous repair technique was developed. The purposes of this article are to review the anatomy, pathology, and existing repair techniques of gluteus medius tendon tears and to describe the rationale and surgical steps for endoscopic trans-tendinous repair.