OBJECTIVES: New health technologies are required to demonstrate both clinical and cost-effectiveness before recommendation by the National Institute for Health and Care Excellence (NICE) for reimbursement in England; however, a large proportion of submissions are rejected due to non-robust economic analysis. Published NICE guidance includes a comprehensive critique of submitted economic evidence so, to help inform future submissions, we assessed the flaws in cost-effectiveness models leading to rejection by NICE. METHODS: All NICE single technology appraisals from January 2006 to May 2014 were included in the analysis. Multiple technology appraisals, resubmissions, vaccination programmes, requests for advice, and submissions where an incremental cost-effectiveness ratio (ICER) could not be determined were excluded. Recommendations and reasoning across decisions were extracted, with a focus on the critique of the economic evidence. RESULTS: