Cost-effectiveness analyses are usually not directly comparable between countries because of differences in analytical and modelling assumptions. We investigated the cost-effectiveness of rotavirus vaccination in five European Union countries (Belgium, England and Wales, Finland, France and the Netherlands) using a single model, burden of disease estimates supplied by national public health agencies and a subset of common assumptions. Under base case assumptions (vaccination with Rotarix®, 3% discount rate, health care provider perspective, no herd immunity and quality of life of one caregiver affected by a rotavirus episode) and a cost-effectiveness threshold of €30,000, vaccination is likely to be cost effective in Finland only. However, single changes to assumptions may make it cost effective in Belgium and the Netherlands. The estimated threshold price per dose for Rotarix® (excluding administration costs) to be cost effective was €41 in Belgium, €28 in England and Wales, €51 in Finland, €36 in France and €46 in the Netherlands.