This paper compares the medicinal uses of animals in fishing communities located in the North and Northeastern regions of Brazil. Data were obtained through field surveys conducted in the Northern state of Pará and in the NE states of Paraíba, Piauí and Maranhão. We interviewed 137 people (67 men and 70 women), who provided information on animal species used as remedies, body parts used to prepare the remedies, and illnesses to which the remedies were prescribed. Comparisons were made using cluster analysis. Interviewees quoted 138 animal taxa, 11 of which are listed in the Brazilian list of threatened species. Animals were used to treat 100 illnesses. Results suggest that similarities in the repertoire of medicinal resources chosen by the surveyed communities reflects both a geographic/cultural continuum and the local accessibility/availability of the resources.