The twist-necked turtle (Platemys platycephala, Schneider 1792) is the only member of the genus Platemys. Despite a pan-Amazonian distribution in South America, ecology and population status of this small, forest-dwelling species are unknown in many countries within its range. Currently it is not listed in the IUCN Red List of Threatened Species, and there are almost no published data on reproduction, feeding, or habitat preferences in the wild. In this article, observations on habitat selection, short-term movements and feeding in the Nouragues Field Reserve, French Guyana, are reported for the first time. Study specimens used the same areas in the late rainy season of 2009 and 2010, moving total distances of 503–686 m over a period of approximately 3 wk within calculated areas of activity ranging in size between 0.73 and 1.59 ha. The main habitats used were palm swamps, temporary flooded forest, and primary nonflooded forest. The analysis of 4 stomach and 2 fecal samples showed that different classes of insects, worms and crustaceans as well as amphibian eggs were consumed as food items.