The content of the lumbar spinal canal can be seen sonographically by anterior approach. An anterior epidural fat is well imaged by sonography and is displaced posteriorly in case of herniated nucleus pulposus. A total of 212 subjects were examined sonographically for the detection of herniated lumbar disc and compared with computerized tomography(CT) and/or myelogrphy in 123 patients. The study population included all men(soldiers) ranging form 18 to 23 years (mean 21 years). The dignosis of herniated lumber disc by CT and/or myelography was made in 101 patients; of whom, 28 bulging discs and 85 herniated nucleus pulposus (Herniated disc at 2 levels in 12 patients) were evident. Thirty patients of them underwent discectomy. Twenty two patients were diagnosed as normal by CT and/or myelography. In 62 out of 85 herniated nucleus pulposus, sonographic diagnosis of herniated nucleus pulposus agreed with CT and/or myelographic examination. The most reliable sonographic findings we e; focal posterior displacement of an anterior epidural fat (N=62), change of the shape of the dural sac (N=60) and narrowing or obliteration of the lateral recess or neural foramen (N=44). Normal disc could not be differentiated from bulging disc by sonography. The results obtained by ultrasound, CT and/or myelography were well correlated in 67%. Sonographic examination can be useful, non-invasive and reliable procedure for the detection of the herniated lumbar disc.