OBJECTIVES: High prices of orphan medicines are a cause for concern as they put pressure on pharmaceutical budgets and may negatively influence patient access to pharmacotherapy. While repurposing of drugs is an attractive strategy to overcome the logistical and financial burden of the first phases of medicine development, we argue that repurposed medicines for rare indications, for which effectiveness evidence has already been published, do not warrant high prices. METHODS: We identified 16 examples of repurposed medicines for rare indications for which effectiveness evidence was published prior to the application for orphan designation and compared Belgian hospital prices between the common disease and the rare indication of the same medicine. RESULTS: In the majority of cases (n = 13), the pharmaceutical form of the medicine was identical for the common and for the rare indication. Medicine prices (per defined daily dose) for the rare indication were nearly the same as for the common disease for cladribine and tadalafil, and ranged from a two-fold difference (e.g. aztreonam, sildenafil) to a 200-fold difference for histamine. Three medicines had a different pharmaceutical form for the rare indication: medicines for the rare indication were at least 56 times more expensive than for the common disease. Hospital prices per dose for the rare indication were at least 23 times higher than for the common disease. CONCLUSIONS: This study suggests that the majority of these selected repurposed medicines for rare indications are over-priced. This pricing practice is not justified and adds to the budget impact of treating rare diseases. There is a need to individually assess repurposed medicines taking into account the costs of research and development and the costs of market access that can be attributed to the medicine for the rare indication as distinct from the costs of the medicine for the common disease.