There is concern about the incidence and serious nature of infection after intramedullary nailing of the tibia, especially for open injuries. We have reviewed 459 patients with tibial fractures treated by primary reamed nailing. The incidence of infection was 1.8% in closed and Gustilo type I open fractures, 3.8% in type II, and 9.5% in type III fractures (5.5% in type IIIa, 12.5% in type IIIb). These incidences appear to be acceptable in comparison with other published results. We describe the different modes of presentation of infection in these cases, and suggest a protocol for its management, which has been generally successful in our series.