Background This systematic review aims to comprehensively summarise and present the available evidence for the treatment of primary acromioclavicular joint (ACJ) osteoarthritis (OA). Methods Five databases were searched for studies investigating the management of ACJ OA. Included were studies with participants with clinical/radiological signs of primary ACJ OA, an intervention and included a functional outcome measure. Results Forty-eight studies were included. Treatments consisted of physiotherapy (n = 1 study), medical only (n = 11) and operative management (n = 36). Operative studies included five comparative trials – physiotherapy versus surgery (n = 1) and open versus arthroscopic resection (n = 4). A total of 1902 shoulders were treated for ACJ OA, mean age (51 years), 58% male and mean follow-up (28.5 months). Treatment with injection showed a mean improvement of 50% in pain levels at follow-up (mean = 7.5 months). The commonest surgical procedure was arthroscopic excision of the distal clavicle and operative studies averaged 6 months of conservative management and a mean functional outcome of 87.8%. Conclusion Studies varied in indication, intervention and quality but it did not provide evidence that both non-operative and operative interventions are effective. There was no significant difference between open or arthroscopic distal clavicle excision (DCE). Participants having between 0.5 and 2 cm of clavicle excised had good outcomes and those requiring concomitant shoulder procedures had similarly good outcomes.