BACKGROUND In the treatment of avulsion fractures of the posterior calcaneal tuberosity, open reduction and internal fixation are prone to several complications. We describe a new treatment using an Ilizarov external fixator, which can minimise the complications and achieve sufficient stability of the displaced fragment. METHODS A 55-year-old woman sustained an avulsion fracture of the calcaneus. Examination revealed the development of bruising with extremely taut skin over the posterior prominence of the displaced bone. Radiographs demonstrated grossly proximal displacement of the tuberosity fragment. Surgery was exclusively percutaneous using an Ilizarov external fixator. The displaced fragment was adequately reduced and stabilised. Progressive weight bearing in the equinus position was initiated at the third week after surgery and the external fixator was removed at the seventh week. There was no skin necrosis or loss of reduction while the fixator was maintained. Postoperative follow-up for 2 years revealed full recovery. CONCLUSIONS Major postoperative complications after conventional open reduction and internal fixation include skin necrosis, skin irritation by metal implants and re-displacement of the reduced fragment. Our method of using an external fixator may decrease the incidence of these three complications. Skin incision and the risk of skin necrosis are inevitable during internal fixation. On the other hand, the use of an external fixator reduces or eliminates skin necrosis, as it is applied percutaneously for reduction and stabilisation of the fragment. External fixation is mostly recommended in cases of poor vascularity or bruising. In addition, skin irritation can be avoided upon removal of the external fixator. Re-displacement occurs occasionally as a serious complication in lag screw fixation, particularly in cases with poor purchase of the osteoporotic bone. Tension band wiring and application of an Ilizarov external fixator in avulsion fractures of the calcaneus can neutralise tension on the Achilles tendon during the healing process. Thus, both these methods are believed to provide sufficient mechanical stability to fix the fragment. CONCLUSIONS This new method, involving application of an Ilizarov external fixator, is recommended when the avulsion fragment is large enough to accommodate Ilizarov wires, especially in cases of circulatory problems or bruising.