H ie authors prasent a new advance In the treatment of herniated disc disease using percutaneous Nd:YAG laser to vaporize a small portion of nucleus pulposus, thereby decompressing the disc In vitro and in vivo animal data are presented. Three hundred seventysovcn magnetic resonance imaging or computed tomography scan-documented, herniated, nonsequesteied lumbar intervertebral discs with corresponding clinical findings in 333 patients wore so treated in an outpatient setting. The longest foJiow-up w as 62 months, with a mean of 26 months. According to ths M a rn sh criteria, there w as a good to fair response in 261 patients (78, 4%), and a poor response in 72 (21.6%): 166 patients experienced relief of pain during the procedure, One-lhird of repeat magnetic resonance imaging scans at 4 - 6 months postfaser treatment showed modest to moderate decrease of disc herniation. © Lippincott-Raven Publishers.