One hundred forty-two patients with malleolar fractures were followed up for an average of 5.7 years postoperatively. In 80 cases (56.4%) we found no lesion of the distal articular surface of the tibia; 62 patients (43.6%) had a fracture of the posterior tibial margin. Both groups were closely matched with regard to fractures of the lateral and medial malleolus. The long-term results were significantly poorer when a fracture of the posterior tibial margin was additionally present, even in cases with a small marginal fragment of the lip of the tibia. Further, we found a clear relationship between the articular involvement and the incidence of post-traumatic osteoarthrosis in cases with no additional osteosynthesis of the fragment. In cases of larger fragments, the long-term results after anatomic reduction and additional osteosynthesis were on the whole far better than in cases treated conservatively.