Background: Diagnosis-related groups (DRGs) are increasingly being used for various purposes in many countries. However, there are no studies comparing different DRG systems in the care of stroke. As part of the EuroDRG project, researchers from 11 countries (i.e. Austria, England, Estonia, Finland, France, Germany, Ireland, the Netherlands, Poland, Sweden and Spain) compared how their DRG systems deal with stroke patients. The study aims to assist clinicians and national authorities to optimize their DRG systems. Methods: National or regional databases were used to identify hospital cases with a diagnosis of stroke. DRG classification algorithms and indicators of resource consumption were compared for those DRGs that individually represent at least 1% of stroke cases. In addition, standardized case vignettes were defined, and quasi prices according to national DRG-based hospital payment systems were ascertained. Results: European DRG systems vary widely: they classify stroke patients according to different sets of variables (between 1 and 7 classification variables) into diverging numbers of DRGs (between 1 and 10 DRGs). In 6 of the countries more than half of the patients are concentrated within a single DRG. The countries’ systems also vary with respect to the evaluation of different kinds of stroke patients. The most complex DRG is considered 3.8 times more resource intensive than an index case in Finland. By contrast, in England, the DRG system does not account for complex cases. Comparisons of quasi prices for the case vignettes show that hypothetical payments for the index case amount to only EUR 907 in Poland but to EUR 7,881 in Ireland. Conclusions: Large variations in the classification of stroke patients raise concerns whether all systems rely on the most appropriate classification variables and whether the DRGs adequately reflect differences in the complexity of treating different groups of patients. Learning from other DRG systems may help in improving the national systems. Clinicians and national DRG authorities should consider how other countries’ DRG systems classify stroke patients in order to optimize their DRG system and to ensure fair and appropriate reimbursement. In future, quantitative research is needed to verify whether the most important determinants of cost are considered in different patient classification systems, and whether differences between systems reflect country-specific differences in treatment patterns and, most importantly, what influence they have on patient outcomes.