Although acromioplasty is widely used in the treatment of subacromial impingement syndrome, there is some con - troversy about the role of acromion morphology in the etiology. The acromion and the coracoacromial ligament provide passive stabilization against upward migration of the humeral head and play an important role in shoulder biomechanics. This article discusses relevant issues on subacromial impingement syndrome pertaining to the acromion and the value of acromioplasty in the treatment.