Compared with acromioclavicular dislocation, dislocation of the clavicle at its sternal end is uncommon and accounts for 3% of all injuries to the shoulder girdle. Furthermore, the posterior dislocation of the sternoclavicular joint is relatively a rare injury compared to the other types of sternoclavicular dislocation. We report this case since we have experience with similar cases of traumatic posterior dislocation at the sternoclavicular joint, which were successfully treated with x-ray guided reduction.