Prosthetic replacement was performed in 31 patients (32 cases) with femoral neck fractures at National Medical Center from 1968 to 1981. We reviewed the records of 28 patients having Austin-Moore prosthetic arthroplasty in 29 cases, and of 3 patients having Thompson prosthetic arthroplasty; then obtained following results. l. Of the 31 patients, 23 were female and 8 were male. The left hip was involved in 20 patients, right in 10, and the both sides in one. 2. The age range was between 35 and 84 years, with the average age of 61.2 years. 74.2% of patients were older than 51 years of age. 3. The most common cause of fracture was slipping or fall (65.6%), and the fracture sites were subcapital in 11 (34.4%), transcervical in 12 (37.4%), and basilar in 3 (9.4%). 4. Three cases (9.4%) were operated within a week, and 21 cases (65.6%) more than 3 weeks after injury. Good results were obtained in fresh fracture which was operated within a week. 5. In comparing the blood loss in Moores and modified Gibson's surgical approaches, the average total loss by the former was 1,290 ml and 1,720 ml by the latter. 6. In complications, one case of fracture of the posterior rim of acetabulum with subsequent subluxation and two cases of fracture of the greater trochanter were notable as operative complicatiens. 7. In a follow-up study averaging 13.1 months, good to excellent results were obtained in 8 cases, fair in 6, poor or bad in 5, respectively.