The acromioclavicular joint (ACJ) is a common cause of shoulder pain. As the majority of shoulder pain originates from the glenohumeral joint and subacromial region, ACJ is often neglected. For this reason the glenohumeral joint and subacromial space and also ACJ must be examined routinely in patients with shoulder pain. Examination of the ACJ with clinical tests, diagnostic injection and proper imaging methods should provide correct diagnosis easily.