The incidence of femoral neck fracture has steadily increased with lengthening of the average life span. The end results of treatement have been improving with the development of internal fixation devices. However, the anatomic characteristics of femoral neck has made the complications of nonunion and avascular necrosis as a common result. Authors analysed 47 patients, with over 2 years follow-up on an average, who were more than twenty years old and treated with multiple Knowles pins or cannulated screws during the period from February 1988 to February 1994. Following results were obtained. 1. Among 47 patients, 23 cases(49%) were male and 24 cases(51%) were female. The highest incidence was found in the sixth decade. 2. The most common cause of femoral neck rracture was slip down(55%). 3. According to the Gardens classification, the displaced fracture(Garden stage III and IV) was more common (68%), and according to the anatomic classification, transcervical type was the most common (40%). 4. Among 47 patients, there were 1 case of nonunion(7%) and 2 cases of avascular necrosis of femoral head(13%) in the nondisplaced fractures(15 cases), compared to 6 cases of nonunion(19%) and 8 cases of avascular necrosis of femoral head(25%) in the displaced fractures(32 cases). There were 4 cases of nonunion(15%) and 5 cases of avascular necrosis of femoral head(19%) among the 26 patients treated with multiple Knowles pins, compared to 3 cases of nonunion(14%) and 5 cases of avascular necrosis of femoral head(28%) among the 21 patients treated with cannulated screws. 3 cases of nonunion(10%) and 4 cases of avascular necrosis of femoral head(13%) were developed among 30 cases in which acceptable reduction was achieved after closed reduction. 4 cases of nonunion(24%) and 6 cases of avascular necrosis of femoral head(35%) were developed among 17 cases in which poor reduction was achieved. 11 cases(42%) were complicated among 26 cases below Singh index grade 3 and 6 cases(29%) were complicat among 21 cases above Singh index grade 4. 5. Factors that may affect the success of treatment in femoral neck fracture are not the type of internal fixation device used, but rather anatomic site of fracture, the degree of displacement, degree of osteoporsis and accuracy of reduction.