OBJECTIVES:  Problematic polypharmacy can lead to adverse drug events, drug-drug interactions, low adherence, reduced quality of life and increased treatment costs. A recent systematic literature review (Christensen & Lundh 2016) found that a medication review may reduce emergency department contacts by 27%. This study aims to estimate the cost-effectiveness of comprehensive medication review (CMR) compared with usual care for patients (≥65 yo) acutely admitted to hospital from the perspective of the UK National Health Service (NHS). METHODS:  A decision analytic model was developed to assess the costs and health consequences associated with interventions over a 12 month time-horizon. The evidence for effectiveness of CMR was derived from the systematic literature review of RCTs, supplemented by routinely collected data (Hospital Episode Statistics). The model followed a conservative assumption that within the 12 month follow-up there was no difference in term of quality of life between the two groups. The main cost of a CMR was assumed to be the additional time for pharmacists to complete the review. Apart from the cost of CMR, the model incorporates the cost to the NHS of emergency department contacts. RESULTS:  The cost-effectiveness of CMR compared to the control arm was dependent on the time taken to complete the intervention by pharmacists. The model indicated that if the CMR takes no longer than 19 minutes to complete it was cost saving. Potential savings ranged from £1 to £20, depending on the time taken (ranging from 1 min to 19 min). The results were similar in subgroup of patients 70 yo; ≥75 yo and ≥80 yo. CONCLUSIONS:  The present study demonstrates that pharmacist-led CMR has the potential to be a cost saving intervention within a 12 month time-horizon. The results were promising and suggest that perusing the analysis of long-term cost-effectiveness is worthwhile.