The authors have studied 32 tarsal coalitions in 20 children. Twenty two were between the talus and the calcaneum, 4 were medial and 6 were rare varieties. The diagnosis is often missed because 40 p. 100 of the children with tarsal coalition had no complaints. The indirect radiological signs have been analysed and precise techniques described for detecting the coalition. Only 11 feet were operated on. On 4 occasions the coalition was simply resected. This always gave a good functional result and good mobility was obtained in the subtaloid joint in 2 cases. The other cases were treated by triple arthrodesis. The authors consider that an earlier diagnosis would lead to better prevention of secondary deformities. The best indication for simple resection is in coalition between the calcaneum and the navicular.