One hundred and fourteen cases of lumbar herniated nucleus pulposus were studied retrospectively. I reviewed the clinical records and radiographs of patients treated with diskectomy and anterior interbody fusion. I followed the patients from 2 years up to 15 years, for an average of 2.9 years. The results were calculated statistically by Fisher exact test and Chi-square test. Among 114 patients, 69 patients (60.5%) were male and 45 patients (39.5%) were female. The most common age group was in its twenties (28.1%), while the whole study group ranged from 19 to 65 years. The most commonly involved level was L_4-5 (73 cases, 60.4%). In clinical results, 83.3% of cases were excellent or good. The rate of solid fusion was 87.8%. The most common type of fusing pattern was type 1. The satisfying clinical result had statistical correlation with the solid union of grafted bone and the fusion state of maintained intervertebral disk height, respectively, by Fisher exact test (p < 0.001). The affecting factors in clinical results were the solid fusion and fusion with the state of maintenance of intervertebral disk height (fusing pattern type I and II). I concluded that anterior diskectomy and interbody fusion is a recommendable method of treatment for lumbar herniated nucleus pulposus.