OBJECTIVES: The British Society for Rheumatology (BSR) Guidelines recommends biological therapies for the treatments of patients with RA as measured by Disease Activity Score (DAS-28) ≥3.2.  Current UK reimbursement Guidance recommends use for biologics to treat patients with RA who have a DAS-28 of ≥5.1 only (severe RA). Our objective is to highlight the need for a review of the eligibility criteria for use of biologic therapies to treat RA in the UK, and to illustrate the number of patients with RA who would be eligible to receive biologic therapies if the criteria of DAS-28 ≥3.2 were to be applied. METHODS: The UK-population estimate was applied to the NICE costing template for biologics for RA, and the number of RA patients eligible to receive biological treatment was calculated. Prevalence rates were based on Symmons. Percentages have been reworked by reference to the population age and sex profile. Based on the Commissioning Guide for biological therapies, which incorporates estimates of patients with a DAS-28 ≥5.1 in whom treatment with disease-modifying anti-rheumatic drugs has failed; 10% patients with RA are eligible for treatment with biologics. Based on clinical opinion collected from a number of leading UK rheumatologists the proportion of patients eligible for treatment with biologics at a DAS-28 score ≥3.2 was estimated to be 50%. RESULTS: The total estimated prevalence of patients with RA is 421,022. Utilising the restrictions outlined in current guidance and applying a DAS-28 score ≥5.1 results in 42,102 RA patients being eligible to receive treatment with biologics. Whereas 210,511 patients would be treated if a DAS-28 score ≥3.2 were to be applied. CONCLUSIONS: Restrictions on UK-guidance leave a significant number patients untreated compared to international guidance. There is widespread agreement that there is a need to make these drugs available to those patients most likely to respond to them.