Clavicle fractures are frequently seen with the recent increase in traffic and industrial accidents. Recently, in adults, open reduction and internal fixation techniques are commonly performed for the patient to return earlier to their jobs. But internsl fixation technique for clavicle fractures has been a subject of controversy. We operated on 78 cases of fractures of the middle third of clavicle by the technique of intramedullary threaded Steinmann pin fixation from March 1985 to Nov. 1988. The following results were obtained. 1. The funtional results were excellent; 32 cases(41%), good; 41 cases(53%), fair ; 5 cases (6%). 2. The complications include motion limitation ; 5 cases(6%), pin tract infection ; 5 cases (6%), delayed union ; 1 case(1%) 3. The advantages of intramedullary threaded Steinmann pim fixation are as follows. 1) Early active range of motion is possible. 2) The operation procedure is simple to perform. 3) Removal of the pin is easy without anesthesia. Therefore, intramedullary threaded Steinmann pin fixation is thought to be a good operative technique for the clavicle fracture.