During 5 years and 8 months, from September 1968 to May 1974, myelographic studies followed by operation werecarried out on 118 cases of lumbar HIVD at Seoul National University Hospital. The myelographic findings andoperative findings were analyzed and following conclusions were obtained. 1. The sex ratio was 75 males to 43females. 2. Among the 118 cases, myelographic findings were consisted of the unilateral defect : 78 cases (67.0%),central defect: 30 cases (25.5%), and, bilateral defects: 10 cases (8.5%) respectively. 3. Among the 118 cases,the greatest incidence was L4-L5 disc space : 87 cases (73.7%) and next incidence was L5-S1 disc space : 25 cases(21.2%) 4. Among the 118 cases of lumbar herniated intervertebral disc disease, the false positive was 8 cases(6.8%) and diagnostic accuracy of myelography was 91.5%. 5. Plain radiography has little value in diagnosis oflumbar herniated intervertebral disc disease among 118 cases, about 30% show significant sign in plain film study.