The aim of the study was to prospectively review the incidence of shoulder injuries in a group of professional rugby union players and to identify any relationship between the injury and the causes, position of play, treatment and time to return to playing. An electronic database system was developed specifically to identify the objectives listed above with a view of reducing injury incidence and recurrence through identification of trends. The system was implemented in both Cardiff(2000–2003) and Llanelli(2005–2007) Rugby Football clubs. Extensive prospective data was collected by the team physiotherapists including: Type of injury(Orchard Coding), playing position, session, mechanism of injury and days lost per injury. Shoulder injuries represented 14% of all injuries sustained. Soft tissue injuries account for about 50% of the injuries and result in an average loss of five playing days. AC joint injuries ( 26%) with a recovery period of 5 days were all treated conservatively. Glenohumeral dislocations caused an average loss of 150 days and all required surgery. Fractures around the shoulder were rare with an incidence of 4%. The most common mechanism for shoulder injury was the tackle (43%). Collisions accounted for 15% of injuries whereas weight training was responsible for 31%. Contact situation training was as risky as real game situations. Back row players were more likely to sustain AC joint injuries. Surgical intervention was needed in only 11% of all shoulder injuries. Our data has shown that most shoulder injuries were from contact related areas. Physiotherapy played a key role in the rehabilitation of these players with surgery only indicated in glenohumeral dislocations and fractures. Careful planning of training sessions with emphasis on tackling and weight lifting techniques may reduce the incidence of such injuries.