Mathematical models have been used extensively in the evaluation of chronic diseases and in exploring the health economics of vaccination. In this study, we examine the value of having two different cohort models based on similar assumptions, one comprehensive and one simplified, which can be used to evaluate the impact of cervical cancer vaccination. To compare models, we ran cost-effectiveness analyses in four geographical regions (Italy, the UK, Taiwan and Canada). We show that the models produce comparable results and therefore can be used independently. However, as they require different complexities of data inputs, they are more suited to different circumstances depending on the level of data inputs available or the complexity of the research question asked. (C) 2008 Elsevier Ltd. All rights reserved.