This study was performed to evaluate a group of patients undergoing percutaneous discectomy. All patients had a single level unilateral L4-5 or L5-S1 disc herniation documented on either computer tomographic (CT) scan, myelogram, and/or magnetic resonance imaging (MRI). Average follow-up after percutaneous discectomy was 16.8 months (range, 2-46 months). The average hospitalization time was 1.7 days (range, 1-5 days). Only 21 patients (55%) were able to return to work after the procedure. Thirteen patients ultimately underwent surgical discectomy for continued symptoms after the procedure. The additional 4 patients did not undergo surgical discectomy and never returned to work. Of those 25 percutaneous discectomy patients who did not undergo surgical discectomy, there was significantly more pain, residual weakness, and numbness compared with the patients undergoing surgical discectomy. The results of this study clearly indicate that percutaneous discectomy does not appear to be as predictable or successful a treatment modality as surgical discectomy.