This study was conducted to investigate the effect of timing of surgery on outcomes of spine operated patients for lumbar herniated intervertebral disc. The research design was cohort study and based on the data of claims for the medical expenses of health insurance. 21,475 cases who had primary spine surgery between January 1, and December 31, 2003, observed to conservative treatment period in the past two years from preoperative primary diagnosis to timing of primary surgery. According to one and five year follow up monitoring, the probability of occurrence of reoperation was not statistically significant with preoperative duration of symptom. Also one year follow up, the probability of occurrence of complication, was not statistically significant with preoperative duration of symptom. But five year follow up, groups who had one to two month preoperative duration of symptom decreased complication rate than less than a month(95%CI:0.594-0.927). Thus, from the onset of symptoms of back pain before primary surgery with enough and adequate time observation is required. Also, medical consumers or providers to choose surgery in determining prudence is required.