The stomach contents of 214 specimens of Hispaniolan Epicrates (Serpentes: Boidae) were examined for prey remains. The largest species, E. striatus, exhibits a sharp ontogenetic shift in diet: snakes < 60 cm SVL ate predominantly Anolis lizards; snakes 60-80 cm SVL took anoles and small rodents; and snakes > 80 cm SVL ate birds and rats (Rattus rattus). Epicrates fordi preyed on anoles and small rodents, and E. gracilis took only Anolis. E. striatus ate larger individuals of the same species of Anolis consumed by Hispaniolan colubrids. Before the arrival of Europeans on Hispaniola, large Epicrates striatus most likely preyed upon birds and now-extict rodents (Brotomys, Isolobodon and Plagiodontia) and insectivores (Nesophontes). The diet of E. striatus would have gradually shifted from native to introduced mammals, and by the early 20th century, when most native, non-volant mammals had become extinct on Hispaniola, the shift would have become nearly complete, with the exotics Mus musculus and Rattus rattus becoming the predominant prey species.