The intramedullary nailing for the fractured tibia has been used in selected cases of fresh diaphyseal fracture and non-union. However, with modern technical improvements, the indications could be expanded considerably. With interlocking nailing technic we can treat various types of tibia fracture, which were unsuitable for intramedullary nailing previously. Stability can be achieved with transverselyinserted bolts which anchor the implant directly to the cortical bone, thereby controllinglength, alignmentandrotation of the fracture as well as permitting early joint motion and weight bearing. Between May 1985 and Feb. 1988, interlocking nailings were performed for 54 cases oftivial fractures, of which 40 cases were acute fracture and 10 were non-union and 4 weremalunion. We obtained the following results ; 1. Closed nailing technic was accomplished in 40 cases and 14 cases were opened. 2. Dynamic and static interlocking nailings were done in 8 and 46 cases respectively. 3. Full weight could be borne on 5th postoperative day in transverse or short oblique fracture cases, 2 weeks in nonunion and malunion cases and 4 weeks in comminuted or segmental fracture cases. 4. The mean fracture healing period was 11.5 weeks in dynamic interlocking cases and 13 weeks in static nailing cases. 5. According to the functional classification of Klemm and Borner, out of 54 cases 36 were excellent, 14 were good, 3 were fair and one was poor.