The objective was to explore the effectiveness of glenohumeral joint distension for the treatment of frozen shoulder. We searched electronic data sources including PubMed, Scopus, and Embase from the earliest records available to February 2017. Eleven randomized controlled trials including at least one pair of comparisons between capsular distension and a reference treatment were included, comprising 747 participants. Patients’ characteristics, details of reference treatments, aspects of capsular distension therapy, and outcome measurement were evaluated at three points in time: baseline, early following intervention, and at the trial’s end. The primary and secondary outcomes were the between-group standardized mean differences of changes in shoulder function and range of motion, respectively. Regarding the long-term primary outcome, the superiority of capsular distension to reference treatments was not identified. One secondary outcome (external rotation limitation) showed a probable early positive response to capsular distension when compared to intra-articular corticosteroid injection. Aspects of approaches, imaging guiding techniques and doses of distension were not found to modify treatment effectiveness. In conclusion, distension of the glenohumeral joint provides a similar long-term efficacy to all reference treatments. A single dose of a corticosteroid-contained regimen introduced through the ultrasound-guided posterior approach is a preferable practice of capsular distension for the management of frozen shoulder.