Background: The usefulness of video-assisted arthroscopic microdiscectomy for the treatment of a herniated lumbar disc has been studied previously. In the current prospective, randomized study, the results of this procedure were compared with those of conventional open laminotomy and discectomy. Methods: Sixty patients who had objective evidence of a single intracanalicular herniation of a lumbar disc caudad to the first lumbar vertebra were randomized into two groups consisting of thirty patients each; Group 1 was managed with open laminotomy and discectomy, and Group 2 was managed with video-assisted arthroscopic microdiscectomy. None of the patients had had a previous operation on the low back, and all had failed to respond to nonoperative measures. Analysis of the outcomes of both procedures was based on the patient's self-evaluation before and after the operation, the preoperative and postoperative clinical findings, and the patient's ability to return to a functional status. The patients were followed for nineteen to forty-two months postoperatively. Results: On the basis of the patient's preoperative and postoperative self-evaluation, the findings on physical examination, and the patient's ability to return to work or to normal activity, twenty-eight patients (93 percent) in Group 1 and twenty-nine patients (97 percent) in Group 2 were considered to have had a satisfactory outcome. The mean duration of postoperative disability before the patients were able to return to work was considerably longer in Group 1 than in Group 2 (forty-nine compared with twenty-seven days). The patients in Group 1 used narcotics for a longer duration postoperatively. No neurovascular complications or infections were encountered in either group. Conclusions: Although the rate of satisfactory outcomes was approximately the same in both groups, the patients who had had an arthroscopic microdiscectomy had a shorter duration of postoperative disability and used narcotics for a shorter period. These findings suggest that arthroscopic microdiscectomy may be useful for the operative treatment of specific symptoms, including radiculopathy, that are caused by lumbar disc herniation, provided that patients are properly selected—that is, they must have a herniated disc at a single level as confirmed on imaging studies, have failed to respond to nonoperative management, have no evidence of spinal stenosis, and have a herniation not exceeding one-half of the anteroposterior diameter of the spinal canal. Moreover, the surgeon must be familiar with this technique and must have received training in its use.