Objective: In accordance with increasing number of elderly people in our society, the incidence lumbar spinal fusion which is technically demanding procedure and requires a lengthy operation time has increased in the patients with lumbar instability over 70 years old. To ascertain the outcome and efficacy of the lumbar spinal fusion in patients over 70 years old. we analyzed the surgical results including complications. Methods: From June, 2003 to May, 2006, we assessed 23 patients over 70 years of age who underwint surgery of lumbar spinal fusion.  Retrospecively, all medical records of these patients were carefully evaluated with regards to types of operations, surgical outcome and complications. Results: Eighty-three percent of the patients showed successful results, and 17% reported poor results Four (4.8%) postoperative complications occurred: two patients with abdominal pain, one patient with voiding difficulty, and one patient with heart problem.  Conclusion: Despite the increase in age and axxociated risk of perioperative complications inherent in this population, an outcome was comparble with that of younger patients reported.