STUDY DESIGN: This study reviewed prospectively 15 patients with chronic persistent low back pain who were treated with disc excision and posterior lumbar interbody fusion(PLIF). Outcomes of treatment were evaluated by a follow-up interview and x-ray studies. OBJECTIVES: To evaluate the efficacy of surgical treatment of patients with chronic persistent low back pain resulting from internal disc derangement (IDD) that does not respond to conservative treatments. SUMMARY OF LITERATURE REVIEW: Chronic persistent low back pain resisting to all known modalities of conservative treatments represents a difficult problem. The efficacy of any specific treatment methods for this group of patients is controversial. MATERIALS AND METHODS: Between 1994 and 2000, 15 patients were treated with disc excision and PLIF at Keimyung University Hospital from 1994 to 2000. The clinical outcomes were evaluated by postoperative follow-up interviews, and the fusion results were evaluated by x-ray studies. RESULTS: All patients responded properly to the follow-up evaluation. 66.6% of the patients had satisfactory results(13.3% excellent, 53.3% good, 26.7% fair, 6.7% poor), and a successful fusion was obtained in all of the patients. CONCLUSION: These results suggest that disc excision and PLIF for IDD patients is effective modality in treatment of IDD.