Studies of the feeding habits of sea turtles are important in identifying their feeding grounds and preferred prey, thus helping with management decisions regarding habitat protection. The present study describes, for the first time, the feeding habits of the sea turtlesCaretta carettaandLepidochelys olivaceain Rio de Janeiro State, south-eastern Brazil (22°06′S–22°55′S). The stomach contents of fiveC. carettaand fiveL. olivacearecovered between 2009 and 2010 were analysed to identify the prey species. A common feeding pattern was noted for both species, with bottom-dwelling prey (fish, crustaceans, molluscs and echinoderms), common in shallow environments, constituting the main food items. All fish and brachyuran crustacean species identified in the stomach contents were by-catch in small-scale shrimp fisheries that operate along the study area. The coastal waters of Rio de Janeiro State represent a new feeding ground forL. olivacea, expanding its preferential habitat during the non-reproductive period. The results provide strong evidence for the likelihood that sea turtles are interacting with fisheries due to an overlapping between feeding and fishery grounds. An evaluation of carcasses washed up on beaches is needed for a better understanding of the effects on the population dynamics of sea turtles.