Objective. To determine the benefits and harm of surgery for shoulder osteoarthritis (OA). Methods. We performed a Cochrane Systematic Review of clinical trials of adults with shoulder OA, comparing surgical techniques [total shoulder arthroplasty (TSA), hemiarthroplasty, implant types, and fixation] to placebo, sham surgery, nonsurgical modalities, and no treatment. We also reviewed trials that compared various surgical techniques, reporting patient-reported outcomes (pain, function, quality of life, etc.) or revision rates. We calculated the risk ratio for categorical outcomes and mean differences for continuous outcomes with 95 CI.