STUDY DESIGN: A retrospective study was performed in elderly patients undergoing lumbar spinal fusion using pedicle screw fixation. OBJECTIVES: To investigate perioperative complications and surgical outcomes in elderly patients who underwent lumbar spinal fusion with pedicle screw fixation. SUMMARY OF LITERATURE REVIEW: There have been few reports regarding the lumbar spinal fusion using pedicle screws in the elderly, especially in the Korean literature. MATERIALS AND METHODS: Thirty-three patients over 60 years of age who underwent decompression and instrumented fusion with pedicle screws were retrospectively evaluated. Minimum follow-up was 2 years. We reviewed medical records and radiological films. We studied age, sex, lesion site, duration of hospital stay, operating time, amount of transfusion, clinical outcomes, complications, preoperative co-morbidity, fusion level, time at which fusion was complete, and fusion rate. RESULTS: The 33 patients consisted of 13 male and 20 female patients. Mean age was 63.8 (60-74) years. Preoperative diagnoses were spinal stenosis, 23, degenerative spondylolisthesis, 8, and spondylolytic spondylolisthesis, 2. Twenty-one cases nvolved single level and 12 cases involved multiple levels. Sixteen patients had 12 co-morbidities. The mean fusion segments ere 1.5 (1-3) segments. The mean operating time was 204.7 (115-330) minutes. The mean amount of transfusion was 2.5 (0-6) ints. The mean duration of hospital stay was 17.8 (13-29) days. Satisfactory clinical outcomes were found in 27 patients (81.8%). usion rate was 93.8%. The time at which fusion was complete was 5.6 (3-12) months. Complication rate was 21.2%. Mortality ate was 3.0%. There was a high postoperative complication rate in patients who had had medical problems before the operation, hich was statistically significant. CONCLUSIONS: Pedicle screw fixation in patients over 60 years was a useful method for the treatment of degenerative spinal disorders. However, patients with preoperative co-morbidity showed a very high medical complication rate. Therefore, careful erioperative management was recommended in high-risk elderly patients with preexisting medical problems.