Due to its anatomical structure and functionality, the shoulder joint is subject to many injuries and damage. Abundant capsule and a significant difference in the size of the articular surfaces allows the performance of movements of a large range of motion, which favors the emergence of shoulder instability. Shoulder instability can be in any direction, and it is most often an anterior instability, in an athlete there is a multidirectional instability and in case of trauma, posterior instability is also possible. The aim of this retrospective study is to investigate the outcome of treatment of patients after atraumatic and traumatic shoulder instability who were surgically treated in Klinika za ortopediju i traumatologiju Lovran in the period from 2011. to 2013. From the collected data on the arrival of postoperative controls and postoperative rehabilitation, it can be concluded that surgery and rehabilitation greatly helped and re-enabled the patient to perform painless movements and normal motor movement control. Taking into account the hypotheses, it can be concluded that there is a possibility of re-injury of the same shoulder or injury of the other shoulder. Timely education of patients on the proper performance of exercise and successful rehabilitation can greatly prevent possible re-injuries or the development of compensatory strategies.