OBJECTIVES: Using a simple method we determined the potential transferability of a previous economic evaluation on the cost effectiveness of adjuvant trastuzumab therapy for the treatment of HER2/Neu-positive breast cancer in Canada (Skedgel et al, 2009) to five other countries (UK, US, Australia, Japan and Germany). METHODS: Based on data from a literature review, we firstly identified all possible transferability factors. From this we selected key transferability factors – those with values that differed across the countries or were factors that were shown to influence the cost-effectiveness ratio in sensitivity analysis in the Canadian reference study. We then considered the ease of transferability (ranging from very low to very high) for each of these potential factors from the Canadian study to the other countries. RESULTS: We identified seven potential key factors for transferability: cost discount rate, health outcomes discount rate, unit costs (particularly drug acquisition cost), resources used, treatment effectiveness, (including duration of benefit) and measures used to determine utility values. Overall, potential transferability was highest for the UK, where treatment practice is similar to that in Canada and data on unit costs, resource use and discount rates are readily available. Because the authors of the reference study did not report unit costs and resource use separately, however, transferability of the analysis was hindered.  Transferability to Australia, Germany and the United States was of an intermediate level, while transferability to the Japanese setting was the lowest because treatment practice is likely to be different, and little cost of illness and utility data exist for that country.   CONCLUSIONS: Several key factors need to be considered when evaluating whether a study is transferable to another setting. To enable the transferability of economic evaluations from one country to another, authors need to ensure that they report their economic data clearly and in sufficient detail.