This paper aims to investigate whether the number of patent requests related to a specific disease can be
considered a reliable and valid measure of pharmaceutical innovation in Brazil. To accomplish this goal, data collection was carried out in the INPI database, concerning patent requests directly related to Chagas disease. The theoretical and the methodological frameworks, applied to interpret the data collection, were elaborated from the rules of inference, developed by Epstein and King, and from the concept of pharmaceutical innovation, formulated by Marcia Angell. Finally, it was possible to infer that the number of patent requests related to a specific disease could be considered a reliable measure of pharmaceutical innovation, if the data mining in the INPI database is guided by accurate, transparent and replicable rules. Moreover, it was also possible to infer that, despite being reliable, the number of patent requests related to a specific disease is not a valid measure, as it can not be considered a facially valid, unbiased, efficient measurement procedure of pharmaceutical innovation in Brazil.