Forty-one children who had forty-two open fractures of the tibial metaphysis or diaphysis were studied retrospectively. Twelve fractures were Type I; eighteen, Type II; six, Type IIIA; four, Type IIIB; and two, Type IIIC, according to the classification of Gustilo et al. All fractures were irrigated and debrided, and antibiotics were given for a minimum of forty-eight hours after the injury. Twenty fractures were initially treated with external fixation and twenty-two, with immobilization in a plaster cast. Three patients had an early infection of the wound, one of which was associated with osteomyelitis; all were successfully treated. The average time to healing of the fracture was five months (range, two to twenty-one months). The time to union was related to the severity of the soft-tissue injury, the pattern of the fracture, the amount of segmental bone loss, the occurrence of infection, and the use of external fixation. There were six delayed unions. Four patients had an angular malunion of more than 10 degrees, which spontaneously corrected in three. One patient who had a proximal metaphyseal-diaphyseal segmental fracture had a progressive valgus deformity. Four patients who had a severe fracture that was treated with external fixation had more than one centimeter of tibial over-growth. There were no amputations. The incidences of compartment syndrome, vascular injury, infection, and delayed union were similar to those reported for open tibial fractures in adults.