OBJECTIVES: Golimumab is a novel TNF-α inhibitor for treatment of patients with severe active ankylosing spondylitis (AS). This study evaluated the cost effectiveness of golimumab and its appropriate comparators in the treatment of AS from UK National Health Service perspective. METHODS: A Markov model with an initial decision tree was developed to simulate the progression of a hypothetical cohort of active AS patients for 20 years. The primary outcome measure was quality-adjusted life years (QALYs) estimated using Bath Ankylosing Spondilytis Functional Index (BASFI) whereas the primary response measure was ≥50% improvement in Bath Ankylosing Spondilytis Disease Activity Index (BASDAI) at 12 weeks. Direct costs including medication costs and AS management costs were included. Golimumab was compared with conventional treatment and other TNF-α inhibitors. Costs and outcomes were discounted at 3.5%. RESULTS: All TNF-α inhibitors were superior to conventional treatment and comparable to each other on BASDAI response. The incremental cost effectiveness ratio (ICER) for golimumab was £15,353 per QALY compared to conventional treatment. The probability of golimumab being cost effective at a threshold of £30,000/QALY was 92%. Compared to etanercept and adalimumab, golimumab generated marginally more QALYs at marginally more costs. CONCLUSIONS: Golimumab may be considered as a cost effective treatment alternative for patients with AS. With comparable costs and efficacy to other TNF-α inhibitors, golimumab’s position in the treatment pathway is likely to be driven by patient and physician choice.