Dislocations of the sternoclavicular joint are uncommon, with the posterior variety having a potential for considerable morbidity. Radiologic management and diagnosis can be difficult. In this review article, the joint anatomy and mechanisms of dislocation are discussed and the incidence and clinical manifestations described. Six case reports are presented to illustrate causative mechanisms, diagnoses, and radiologic appearances. Computed tomography is the best method of demonstrating the sternoclavicular joint, but a number of specialized plain film projections are also described and illustrated; these should be more widely known. Treatment of the joint dislocations is briefly discussed.