Three hundred and fourty two patients with a fracture of tibial shaft were treated and managed in the Department of Orthopaedic Surgery, Soon Chun Hyang University Hospital from January 1981 to December 1985. In 147 cases, 62 cases had only tibial shaft fracture and 85 tibial and fibular shaft fracture. All of these were treated conservatively by manipulation and cast immibilization. We analyzed the initial fracture characteristics, the treatment employed, and the subsequent complications in fracture healing in a series of patients who had sustained a tibial shaft fracture with and without a fibular fracture. The results were as follows; 1. Duration of average bone healing was more slowly in the patients more than twenty years old who were treated for a tibial shaft fracture with and without a concomitant fibular fracture than in the patients less than twenty years old. 2. Duration of average bone healing was more slowly by one or two weeks in the the group of tibial shaft fracture without fibular fracture than in than in those with fibular fracture. 3. The frequency of delayed union, nonunion, varus malunion and pain in the ipsilateral ankle joint were more increased in the group of the tibial shaft fractures without fibular fracture in than those with fibular fracture. 4. The frequency of valgus malunion was more increased in the group of the tibial shaft fractures with fibular fracture than in those without fibular fracture.