OBJECTIVES: Chronic spontaneous urticaria (CSU) is characterised by rapid appearance of wheals, angioedema or both, with no obvious cause and with symptoms lasting for more than six weeks; CSU has a demonstrable negative impact on patient quality of life and societal productivity. The objective of this study was to assess the cost-utility of omalizumab compared with continued standard of care (SOC) for the treatment of patients with moderate or severe CSU with an inadequate response to SOC, from the UK societal perspective. METHODS: A Markov model was developed, defined by five disease severity health states and three additional states for relapse, spontaneous remission and death. The model considered 6 month courses of omalizumab treatment, with re-treatment upon relapse (relapse definition: UAS7≥16) and early discontinuation of non-responders (definition of response: UAS7≤6). Clinical and cost inputs were derived from omalizumab trials and published sources; productivity inputs were informed by a non-interventional study and average earnings data. The base case considered a 20-year time horizon, and cost-utility was expressed as an incremental cost-effectiveness ratio (ICER). Scenario analyses included no early discontinuation of non-responders and an altered definition of response (UAS7<16). RESULTS: In the base case analysis, the deterministic ICER was £3,183, with omalizumab being associated with increased costs and increased benefit relative to SOC. Probabilistic sensitivity analysis supported this result. Individual scenarios without early discontinuation of non-responders and adjusting the definition of response had little impact on results (ICERs £4,409 and £5,304, respectively). Further sensitivity analyses demonstrated robustness of results to changes in key model parameters and inputs. CONCLUSIONS: To our knowledge, this is the first economic evaluation of omalizumab in CSU from a UK societal perspective. Omalizumab was associated with consistently low ICERs across a range of different scenarios, demonstrating omalizumab to represent a treatment option with societal benefit for CSU in the UK.