We report the use of Grosse-Kempf reamed intramedullary nailing in the treatment of 41 Gustilo type II and III open tibial fractures. The union times and infection rates were similar to those previously reported for similar fractures treated by external skeletal fixation, but the incidence of malunion was less and fewer required bone grafting. The role of exchange nailing is discussed and a treatment protocol is presented for the management of delayed union and nonunion.