With the growing international literature in economic evaluation and the rapid spread of new health technologies, there is a need to undertake, or at least interpret, economic evaluations on the international level. However, the ways in which cross-national differences affect the cost-effectiveness of health technologies or their evaluations have never been studied. This paper explores these issues by taking advantage of a unique situation in which the same economic evaluation of a new indication for a health technology was conducted simultaneously in four countries using an identical methodology. The study showed that if prior agreement on methods can be reached and local data applied, economic evaluations can be undertaken in a way that facilitates the extrapolation of results from country to country.