Twelve cases of posterior sternoclavicular dislocation were seen over 15 years at the Victoria General Hospital and the Izaak Walton Kiliam Hospital for Children in Halifax, NS. Two patients required open reduction of the dislocation but the rest were treated by closed reduction. One of the former group required threaded K wires for stability, but all other dislocations were deemed stable after reduction and application of a figure-of-eight bandage and an arm sling. There were no failures of reduction and no recurrent dislocations; the authors have been successful even in late closed reduction (up to 5 days) and therefore recommend it highly as the primary treatment. Open reduction is much more difficult and hazardous.