The operative treatment of intraarticular calcaneal fractures has three principal aims; restoration of the height and width of the calcaneus, reconstruction of the subtalar and calcaneocuboid joint surfaces, and stable osteosynthesis. The purpose of this study is to demonstrate the effectiveness of the open reduction and internal fixation by the extended lateral approach for the treatment of the intraarticular calcaneal fractures. Twenty-one calcaneal fractures of 20 patients were treated by open reduction and internal fixation using an extended lateral approach from April, 1993 to March, 1994. The autogenous iliac bone graft was done in all patients. These patients were evaluated from 12 to 24 months (average 15.2 months) after surgery. The following results were obtained; 1. Seventecn cases (80%) out of 21 were estimated as good or excellent result. 2. Preoperative Bohler's angles, Gissane's angles and inclination angles were observed as average -0.5degrees, 101degrees and 38degrees respectively, and these were improved as average 23.3degrees, 117degrees and 54degrees, postoperatively. 3. There were two cases of skin necrosis as complication. In conclusion, the extended lateral approach is one of the good methods for the treatment of intraarticular calcaneal fractures. We think that accurate reduction of the posterior facet, acceptable recovery of Bohler's angle and early postoperative mobilization are the most important things for the best result of the intraarticular calcaneal fracture surgery.