Pierre Auguste Broussonet appears to be the first researcher engaged in the study of the fishes from the Portuguese collections on Natural History, and especially the Royal Museum of Ajuda collections, including the utmost important one collected in Brazil by Alexandre Rodrigues Ferreira. He also dealt with the collection of fishes from the Royal Academy of Sciences, the institution that supported him during his stay of approximately four months in Lisbon, where he arrived sometime in September or October 1794. An experienced Naturalist, especially on Ichthyology, he produced a pioneer work on an entirely unknown collection, that of the Royal Academy of Sciences of Lisbon. This collection had certainly been transferred from the Royal Natural History Museum at Ajuda. Our present status of knowledge is largely based on documents from the Bibliothèque Centrale of the Muséum national d'Histoire naturelle, Paris. The document on fishes from the Academy's Museum (Table 3) is evidence for the intervention of Broussonet. This document is therefore and by far the more important one as far as Broussonet's intervention is concerned. Broussonet is thus a remarkable pioneer of the scientific cooperation between Portugal and France.