To investigate whether subacromial corticosteroid injections are effective in the treatment of rotator cuff disease, an evidence-based systematic review was undertaken of nine randomized controlled trials that compared subacromial corticosteroid injection with placebo in patients with rotator cuff disease. Each study was systematically evaluated for biases, and outcome measures were scrutinized for statistical significance and clinical importance. One study demonstrated clinically important differences in pain relief. Two studies showed clinically important improvement in range of motion at final follow-up. This systematic review of the available literature indicates that there is little reproducible evidence to support the efficacy of subacromial corticosteroid injection in managing rotator cuff disease.