STUDY DESIGN: Seventy femoral neck fractures in the elderly patients aged over 60 years treated with osteosynthesis or primary biploar arthroplasty were assessed on complication and functional outcome at final follow up. OBJECTIVE: To compare the results of femoral neck fractures in the elderly patients aged over 60 years treated with osteosynthesis or primary bipolar arthroplasty retrospectively. To know the indications of each method. SUMMARY OF BACKGROUND DATA: Althrough the osteosynthesis method had preservation of hip joint, primary osteosynthesis method had possibility of major complications as nonunion and avascular necrosis of femoral head. METHODS: Seventy patients with intra-articular femoral neck fracture were treated with osteosynthesis in 33 patients(group 1) and primary biploar arthroplasty in 37 patients(group 2). A comparartive analysis of age, sex, type of fracture, initial displacement of fracture, method of treatment, fixation device type, quality of reduction, operative time, blood loss at operation, complication and functional outcome at final follow up were performed. RESULTS: The female was more three times than male. The mean ages were 70.1 years old in group 1 and 73.3 years old in group 2. In group 1, complications such as non-union and avascular necrosis of femoral head were significantly greater in the subcapital fractures and Garden's stage 3,4 than the transcapital fractures and Garden's stage 1,2. In operative method, blood loss and operative time were significantly greater in the group 2 than in the group 1. Seven major complications (avascular necrosis: 6 cases, non-union: 1 case) occurred in group 1, two major complications(death: 2 cases) occurred in group 2. The functional outcomes were superior to the group 2, but it may be due to high complication rates in group 1. CONCLUSIONS: This study suggests that the important factors that influenced the clinical results were type of fracture, initial displacement of fracture, quality of reduction. So in relatively poor arthroplasty.