The Little Oakley channel has provided one of very few stratified early Middle Pleistocene vertebrate faunas from the British Isles. This study is based both on material recovered by S. H. Warren in 1939, and new material excavated in 1982-87. The vertebrate fauna is entirely consistent with a temperate climate and vegetation, in keeping with palaeobotanical and invertebrate evidence from the site. Mammals include taxa indicative of both woodland (e.g. Apodemus sylvaticus, Sus scrofa), and more open areas (e.g. Equus sp., Sorex minutus). At least 12 species of freshwater fishes have been identified, including the first British Pleistocene records of carp (Cyprinus carpio), freshwater burbot (Lota lota), and probably zander (Stizostedion sp.). The herpetofauna includes the earliest dated British record of European pond tortoise (Emys orbicularis), which together with the fish fauna indicates fully interglacial conditions. The early giant deer Megaloceros verticornis and probably M. dawkinsi are recorded for the first time in Britain outside the Cromer Forest-bed Formation. These species, together with the ancestral water vole Mimomys savini, are of considerable stratigraphic significance, strongly supporting an age for the channel later than Pastonian but pre-dating faunas 2 and 3 of Westbury-sub-Mendip.