Rotator cuff injuries represent a significant burden to the health care system, affecting more than 30% of the population over the age of sixty. Despite the advanced surgical techniques that are available, poor results are sometimes seen in a subset of patients receiving surgical treatment for their rotator cuff disease. The reasons for this failure of treatment remain unclear, particularly if the surgery was ‘technically’ successful. An increasing body of evidence has demonstrated a strong correlation between pre-operative psychological factors and functional outcome following several orthopaedic procedures. This association, however, has not been fully demonstrated or effectively investigated in the context of rotator cuff treatment. The main objective for this study was to conduct a systematic review to determine the impact of psychosocial factors on the outcome of treatment in patients with rotator cuff disease. A systematic search was conducted of Medline, CINAHL, and PsychInfo databases for articles published from database inception until September 2018. The titles and abstracts were screened for all of the studies obtained from the initial search. Inclusion and exclusion criteria were applied, and a full text review was conducted on those studies meeting the eligibility criteria. A total of 1252 studies were identified. Following removal of duplicates and application of the inclusion and exclusion criteria, 46 studies underwent a full-text review. Ten studies were included in the final analysis. A total of 1,206 patients, with a mean follow-up of 13 months, were included. Three studies examined patient expectations prior to treatment. All three found that higher expectations prior to treatment led to a significantly improved outcome following both operative and non-operative treatment. Three studies assessed the association between pre-operative general psychological measures and post-operative pain and function. All three studies found patients with worse pre-operative general psychological scores demonstrated increased post-operative pain. Two of the studies also found a negative association with post-operative function, while one of the studies found no association with post-operative function. Three studies assessed the impact of pre-operative anxiety and depression on outcomes following surgical treatment of rotator cuff disease. Only one of the studies found a negative association with post-operative pain and function. The remaining two studies found no association between anxiety or depression and any outcomes following surgery. Finally, one study examined the impact of general distress on outcomes following the surgical treatment of rotator cuff disease and found no association with post-operative levels of pain or function. The results of this systematic review indicate that there is somewhat conflicting and contradictory evidence within the literature. Overall, however, there does appear to be an association between pre-operative psychological factors and post-operative function and pain, in that higher levels of pre-operative psychological dysfunction are predictive of poorer function and increased pain following the treatment of rotator cuff disease.