Cannibalism is the total or partial consumption of a conspecific’s body or eggs, and it has been reported for many bird taxa, particularly carnivorous, colonial species, and those species that ingest fragmented prey. Here we report cannibalism by Brown Booby ( Sula leucogaster ) at Saint Peter and Saint Paul Archipelago, offshore Brazil. We discussed possible causes for this behavior such as opportunistic feeding, colony sanitation and space competition for nesting places.