The validity of the cardiac surgical scoring system, EuroSCORE, has been assessed by several individual cardiac centres within and outside Europe. We chose to assess the overall international performance by systematic review of peer-reviewed literature. There were six studies meeting our criteria for assessment. Internationally, the evidence is highly suggestive that additive EuroSCORE performance generally over-estimates mortality at lower EuroSCOREs (EuroSCORE13). The effect of this could have serious misrepresentations for surgeons and hospitals operating on differing case-mixes. We suggest that further studies need to be performed on the logistic EuroSCORE calculation to ascertain whether predictive ability is improved. Overall, however, EuroSCORE is the most rigorously evaluated scoring system in cardiac surgery.