Fractures of the clavicles are extremely common, accounting for 5 to 10% of all injuries in the adult skeletal trauma. Despite this, nonunions and symptomatic malunions after clavicular fracture are uncommon. When these complications occur, however, they may be associated with 11 pattern of disability that includes not only pain but also impairment of upper extremity function. The purpose of this study was to clarify the outcome of clavicular fractures treated by conservatively, and emphasize treatment and factors that possibly predispose a clavicular fracture to poor function or nonunion. We evaluated 9] consecutive fractures of the middle-third of the clavicle in adults which had been treated conservatively. There were 59 males and 33 females ranging in age from 17 to 80 years (average 36.8 years). Nine of the 91 fractures (10%) had developed nonunion, and 4 fractures (4.4%) reported unsatisfactory results. No patients had significant impairment of range of motion or strength as a result of the injury. We found that initial shortening at the fracture of≥20mm(6 cases) had a highly significantly association with nonunion(P<0.0001). Final shortening of 20mm or more (4 cases) was associated with an unsatisfactory result, but not with nonunion(P<0.0001). Our results have led us to recommend the open reduction and internal fixation of severely displaced fractures of the middle third of the clavicle in adults patients.