Caimans (Crocodilia: Alligatoridae) are top-level predators in aquatic ecosystems of the Neotropics. This paper presents data on the diet of caimans from the Peruvian Amazon (principally Paleosuchus spp., but also Caiman crocodilus and Melanosuchus niger), including feeding observations and stomach content examinations. A total of 58 stomach content analyses and three in situ feeding observations were made, and incidence of gastric parasitism and external injury were also studied. Insects, crustaceans, and fish were the most frequently encountered prey in the gut of P. trigonatus, but reptiles, fish, crustaceans, and mammals composed the greatest proportion of the diet by stomach content dry mass. We report novel squamate and fish species in the diet of Amazonian caimans and overall dietary findings consistent with that of other caiman diet literature. Gastroliths were absent from C. crocodilus and M. niger, although 44% of P. trigonatus sampled contained gastroliths. Parasitic nematodes were recovered from just under half of sampled C. crocodilus and P. trigonatus and 71% of M. niger. Injury rates were low in M. niger and P. trigonatus (< 10% of individuals) while 35% of C. crocodilus were injured, most often through damage to the tail. These data on caiman diet, gut parasitism, and injury rates help provide a baseline for comparison between species and study populations.