BACKGROUND: Conventional microdiskectomy is the most frequently performed surgery for patients with sciatica caused by lumbar disk herniation. Transmuscular tubular diskectomy has been introduced to increase the rate of recovery, although evidence of its efficacy is lacking. OBJECTIVE: To determine whether a favorable cost-effectiveness for tubular diskectomy compared with conventional microdiskectomy is attained. METHODS: Cost utility analysis was performed alongside a double-blind randomized controlled trial conducted among 325 patients with lumbar disk related sciatica lasting >6 to 8 weeks at 7 Dutch hospitals comparing tubular diskectomy with conventional microdiskectomy. Main outcome measures were quality-adjusted life-years at 1 year and societal costs, estimated from patient reported utilities (US and Netherlands EuroQol, Short Form Health Survey-6D, and Visual Analog Scale) and diaries on costs (health care, patient costs, and productivity). RESULTS: Quality-adjusted life-years during all 4 quarters and according to all utility measures were not statistically different between tubular diskectomy and conventional microdiskectomy (difference for US EuroQol, -0.012; 95% confidence interval, -0.046 to 0.021). From the healthcare perspective, tubular diskectomy resulted in nonsignificantly higher costs (difference US $460; 95% confidence interval, -243 to 1163). From the societal perspective, a nonsignificant difference of US $1491 (95% confidence interval, -1335 to 4318) in favor of conventional microdiskectomy was found. The nonsignificant differences in costs and quality-adjusted life-years in favor of conventional microdiskectomy result in a low probability that tubular diskectomy is more cost-effective than conventional microdiskectomy. CONCLUSION: Tubular diskectomy is unlikely to be cost-effective compared with conventional microdiskectomy.