OBJECTIVES: Minimally invasive surgery techniques (MIS) for lumbar spine fusion allow surgical treatment of back and leg pain while aiming at minimizing tissue injury and accelerating patient recovery. The objective of this study was to estimate the cost-effectiveness of MIS compared to open surgery (OS) for the treatment of degenerative lumbar spinal conditions in a UK setting. METHODS: Resources, costs and differences in Health Related Quality of Life (HRQoL) after MIS and OS were based on a literature review or derived from other public sources. Resources included were: staff and operating room, surgical equipment, consumables, blood loss, surgical drainage, duration of hospitalization and post-operative complications. In the base case it was assumed that the surgeons hadn’t reached the top of the learning curve. The cost-effectiveness was expressed as the incremental cost per QALY gained using a time horizon of two years after surgery. The costs included the total direct medical cost associated with either procedure and the utility gain was estimated from the Swedish national spinal registry data. RESULTS: Modeling showed that MIS was the dominant strategy vs. open surgery yielding both cost savings and improved HRQoL. Cost savings were driven mainly by shorter length of hospital stay, less blood loss and fewer complications. The total cost-saving was £639 per procedure with a small improvement in HRQoL (0.04 QALY gain after 2 years). CONCLUSIONS: MIS may be a dominant treatment option compared to OS for spinal lumbar fusion in a UK setting. Lower costs and increased HRQoL in the MIS group compensate for potential higher upfront costs of MIS implants and equipment. Future analyses should consider the inclusion of indirect costs as the majority of the patient population is below age 65 and will potentially return to work.