Retrosternal dislocations of the clavicle is an uncommon lesion which in unskilled hands may be difficult to diagnosis, with the result that treatment is often delayed. In most of the previously reported cases, delay has necessitated the use of open operation and internal fixation. In the series of six cases presented here, early diagnosis and treatment made the use of closed reduction possible and resulted in an uncomplicated postreduction course with no significant permanent disability. Since roentgenographic findings are sometimes inconclusive, the importance of suspecting this lesion in any sternoclavicular injury is stressed, early clinical examination being the most conclusive means of diagnosis. In some cases the diagnosis can be made definite only by the characteristic signs of reduction of the dislocation.