The use of subacromial injections to treat shoulder pain has remained one of the most common procedures for the practicing orthopedist, rheumatologist, and general practitioner. Despite this, many prospective studies have questioned the efficacy of corticosteroid injections compared with nonsteroidal anti-inflammatory drugs or injections of local anesthetics alone, or both, when used for the treatment of symptomatic rotator cuff disease. Accurate diagnosis of the etiology of a patient's shoulder pain and proper injection technique are important in achieving satisfactory clinical outcomes. Both extrinsic as well as intrinsic etiologies for rotator cuff disease should be considered and must be elucidated with appropriate physical examination techniques. Although subacromial injections appear straightforward, more recent cadaveric, radiographic, and clinical studies have demonstrated variable accuracy rates using the two common techniques. In addition, absolute sterile technique must be used because infections of the subacromial space after injections, although uncommon, have generally led to debilitating conditions. This article reviews the etiology and pathophysiology of rotator cuff disease and the indications and techniques for subacromial corticosteroid injections.