The genus Strepsylla Traub is redescribed and compared with the other genera of the tribe Phalacropsyllini. Thirteen recognized species are distributed in Mexico, Guatemala, Honduras, Costa Rica, and Panama, where they parasitize small rodents, especially mice of the genus Peromyscus. Five new species are reported and described (Strepsylla ixtlanensis n. sp., Strepsylla longicauda n. sp., Strepsylla queretana n. sp., Strepsylla tezontli n. sp., and Strepsylla vargasi n. sp.). Keys for the genera of the tribe and for the species of Strepsylla are included, and relevant notes for each species are given. A cladistic analysis of Strepsylla led to the recognition of 2 clades: one includes S. mina, S. villai, and S. tezontli, which are distributed along the Trans-Mexico Volcanic Belt; and the other includes the remaining species, which have a northern Mexico distribution.