Background: Although segmental wire fixation has been successful in the treatment of nonathletes with spondylolysis, no information exists on the results of this type of surgery in athletes. Purpose: To evaluate the outcome of surgical repair of pars interarticularis defect by segmental wire fixation in young athletes with lumbar spondylolysis. Methods: Between 1993 and 2000, 20 athletes (6 women and 14 men; average age, 23.7) with lumbar spondylolysis were treated surgically with this technique. They were actively engaged in sports such as baseball, tennis, and golf. Nineteen athletes had one level of spondylolysis and one athlete had two levels. The level of spondylolysis was L4 in 2 athletes and L5 in 19. The average follow-up period was 3.5 years (range, 1.3 to 8.6). Surgical outcome was evaluated by radiographic examination, the Japanese Orthopaedic Association score, preoperative and postoperative sports activity levels and intensities, and the presence of complications. Results: Bony fusion at the site of spondylolysis was obtained in all cases, and the Japanese Orthopaedic Association score was increased significantly after surgery (preoperatively, 21.2 +/- 3.9; postoperatively, maximum 27.7 +/- 1.0; recovery rate, 80.4%). All of the patients returned to their sports activities, although at varying degrees. No severe complications were noted. Conclusion: We recommend this technique in cases of lumbar spondylolysis in athletes who hope to resume their sports activities. (C) 2003 American Orthopaedic Society for Sports Medicine.