The goal of the treatment of femoral neck fractures is early ambulation to prevent the complications such as pneumoniae or atelectasis, deep vein thrombosis, pulmonary embolism, bed sore, general weakness. The authors have tried to asess the outcome and complication of multiple pinning (28 cases) and biploar endoprosthesis (35 cases) for femoral neck fractures in average 18 momths with the range of 12 months to 5 years from May 1990 to May 1996. The results were asessed by interval from injury to operation, post operative complication and mortality rate, weight bearing time, Lunceford hip grading method. The results were as folllows: 1. Post operative complications rate were 43% in multiple pinning, and 26% in bipolar group. 2. The mortality rate was 14.2% in multiple pinning group and 11.4% in bipolar endoprosthesis group. 3. The functional results evaluated by Lunceford's methods were satisfactory in 64% of multiple pinning group and 71% in bipolar endoprosthesis group. We concluded that displaced fractures, subcapital fracture, severe osteoporosis, old fracture over 3 weeks in elderly patients, bipolar endoprosthesis gave a more reliable results.