Rotator cuff disease is the most common cause of shoulder pain and dysfunction in adults. Despite the significant amount of pain and disability related to rotator cuff pathology, there is insufficient information to guide the clinician in planning therapeutic interventions. In this article, we reviewed the anatomy, biomechanics, and pathophysiology of the rotator cuff in an attempt to cover recent literature the reof. A consensus is now emerging that the etiology of rotator cuff disease is multifactorial, including extrinsic and intrinsic factors. Further investigations are needed to clarify the mechanisms and the pathogenesis of rotator cuff disease, as well as the effectiveness of various treatment modalities.