Bats of the family Phyllostomidae are fundamental components of Neotropical mammalian diversity and display the greatest dietary diversity seen in any mammalian family. We studied trophic structure in a species-rich local assemblage of phyllostomids for which dietary data were collected during 10 years on Barro Colorado Island, Panama. Correspondence analysis of >3800 dietary records from 30 syntopic species showed a structure supporting traditional divisions of animalivorous and phytophagous phyllostomids. Putatively omnivorous species actually grouped among the latter. Phytophagous phyllostomids separated into Piper-specialists, Ficus-specialists, and eclectic plant eaters which in turn were the main consumers of flower products. Discrete dietary groups were compatible with several clades of the two current phylogenetic hypotheses of phyllostomids. We show that the trophic structure of the local contemporary assemblage is largely conservative with respect to traceable ancestral habits, strongly suggesting that overall trophic structure was likely determined historically.