Although operative treatment for lumbar disc herniation is a commonly performed neurosurgical procedure, no reports have described whether health-related quality of life before surgery affects the operative treatment outcome. This prospective study assessed health-related quality of life before and after surgery and evaluated the predictor variables affecting outcomes. Subjects were 45 consecutive candidates for lumbar disc herniation surgery who gave informed consent. The Medical Outcomes Study Short Form 36 (SF-36) and 15-point Japanese Orthopaedic Association (JOA) score were evaluated before and after surgery, and the magnitude of the effect was calculated. The possible predictor variables for outcomes were physical functioning, role physical, bodily pain, general health, vitality, social functioning; role emotional and mental health from the SF-36 subscales; subjective symptoms and clinical signs from the JOA scores; and the patient's age, sex, occupation, and history of low back pain and/or leg pain. Four patients were excluded from the analyses because they were lost to follow-up within 1 year after operation. All subscales of the SF-36 and JOA scores increased significantly at 6 months and 1 year of follow-up with a maximum effect size in bodily pain and a minimal in general health. Operation results were 29 good, 11 fair, and 1 poor. The selected predictor variables affecting the outcomes were patient age and social functioning on SF-36. Surgery for lumbar disc herniation improved health-related quality of life. Patients <50 years old with a <60 score in social functioning on SF-36 were considered good candidates.