The incidence of herniated lumbar disc under the age of 19 years is increasing due to increased sports activity of teenager and development of diagnostic methods. 33 cases of herniated lumbar disc of the teenager was analyzed at Department of Orthopaedic Surgery, Dong-A College of Medicine from March 1990 to May 1994. The results were obtained as follows: 1) Among 413 patients, 33 patients(7.9%) were teenagers and the sex ratio was 2.3:1 in male to female. 2) Average intervals between the onset of clinical symptoms and the admission were 13.2 months. 3) 20 cases(60.6%) had a definite trauma history, and among these cases, 14 cases(70.0%) were associated with sports activity. 4) The most common level of herniation was L4-5 in 29 cases(64.4%), straight leg raising test was positive in 32 cases(97.0%), sensory change in 13 cases(39.4%), motor weakness in 10 cases(30.3%). 5) Among positive MRI findings(32 cases), 17 cases(53.1%) were the protruded type. 6) Among 23 operative cases, 21 cases had excellent or good results.