A collection of about 500 molars from 5 Pleistocene localities on the island of Bonaire (off the coast of Venezuela), previously identified as Thomasomys sp., is reidentified as representing a new genus and 2 new species of oryzomyine rodents based on comparative examination and phylogenetic analysis of morphological characters. The material from 1 of the 5 localities is distinguished by its smaller size and several discrete characters; a larger species is represented in the other 4 localities. In addition, a single edentulous dentary represents a different species that is described as an indeterminate genus and species of Sigmodontinae.