OBJECTIVES: To identify differences in the availability of orphan drugs and in patient access to them in eleven pharmaceutical markets: Australia, Canada, England, France, Germany, Hungary, the Netherlands, Poland, Slovakia, Switzerland and the US. METHODS: Four rare diseases were selected for analysis: pulmonary arterial hypertension, Fabry disease, hereditary angioedema and chronic myeloid leukaemia. Indicators for availability were defined as the indications for which orphan drugs had been authorized in the treatment of these diseases, the application date and the date upon which these drugs received market authorization in each country. Indicators of patient access were defined as the outcomes of technology appraisals, the extent of coverage provided by health care payers and the price of the drugs in each country. RESULTS: Most drugs included had received market authorization in all countries, but the range of indications for which they had been authorized differed by country. The broadest range of indications was found in Australia, and the largest variations in indications were found for PAH drugs. Authorization process speed, the time between application and market authorization, was fastest in the US with an average of 362 days followed by the EU (394days). The highest prices for the included drugs were found in Germany and the US, and the lowest in Canada, Australia and England. Although the prices of all of the included drugs were high compared to those of most non-orphan drugs, most of the insurance plans in our country sample provided 100%coverage for authorized drugs after a certain threshold. CONCLUSIONS: Although the present study showed some variations in selected indicators of availability and access to orphan drugs, virtually all of the drugs in question were available and accessible in our sample. Substantial copayments in the US and Canada, however, represent barriers to patient access, especially in the case of expensive treatments.