Fasciola hepatica is a worldwide emerging and re-emerging parasite heavily affecting several regions in South America. Some lymnaeid snail species of American origin are among the major hosts of F. hepatica worldwide. Recent paleoparasitological findings detected its DNA in a 2300-year-old sample in Patagonia, countering the common hypothesis of the recent arrival of F. hepatica in the Americas during European colonization. Thus, the theory of an initial introduction in the 1500s can no longer be sustained. This article discusses how it was possible for F. hepatica to reach and spread in the Americas in relation to the availability and compatibility of hosts through natural and incidental introductions. Our study will serve to better understand the ongoing Neotropical scenario of fasciolosis.Fil: Vázquez, Antonio A.. Instituto de Medicina Tropical Pedro Kouri; Cuba. Centre National de la Recherche Scientifique; FranciaFil: Alba, Annia. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Alda, Maria del Pilar. Centre National de la Recherche Scientifique; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Vittecoq, Marion. Centre National de la Recherche Scientifique; Francia. Research Institute for the Conservation of Mediterranean Wetlands; FranciaFil: Hurtrez Boussès, Sylvie. Centre National de la Recherche Scientifique; Francia