The phyllostomid bat genus Vampyressa often has been allied with Uroderma, Chiroderma, Platyrrhinus, Vampyrodes, and Mesophylla. However, the relationships among the genera have proven difficult to resolve, and a number of studies have suggested that Vampyressa is not monophyletic. Mesophylla includes a single species, which some taxonomists have placed in Vampyressa and others in the more distantly related genus Ectophylla. Our analysis of sequence data from the cytochrome-b gene (Cytb) gives strong support for Mesophylla being closely related to Vampyressa, rather than Ectophylla. Examination of the Cytb data indicates that Vampyressa pusilla and Mesophylla are members of a lineage distinct from V. bidens and V. brocki. Therefore, we recognize the genus Vampyriscus for V. brocki and V. bidens. Brazilian specimens of V. pusilla are strongly divergent from specimens from elsewhere in Latin America. The degree of genetic distance indicates species-level divergence between these taxa, and supports the recent recognition of Vampyressa thyone for the northern populations.