Mammal faunas referred to the late-Middle Pleistocene have been known for a long time from Latium, especially from the 'Bassa Campagna Romana', where the explosive products of the Sabatinian and Alban volcanic districts are interbedded with sedimentary cycles, that represent alluvial fills. The faunas have been examined by several authors but discordant opinions have been expressed about the age of the beds where the faunas were found. The faunal associations of Castel di Guide-La Polledrara-Malagrotta, Riano Flaminio and Torre in Pietra (lower beds) belong to the first sedimentary cycle named the Aurelia Formation, which is related to oxygen isotope stage 9. The character of these faunas suggests several cool-temperate oscillations within this stage and the presence of an open environment along the coast, whereas, inland, deciduous forests, indicating moist temperate conditions, were present. The associations of Torre in Pietra (upper beds), Vitinia, and Sedia del Diavolo are referred to a second sedimentary cycle, named the 'Vitinia Formation', related to oxygen isotope stage 7; these associations are modern in character, and are generally dominated by fallow deer. The climatic conditions were warm-temperate and wet, with an expansion of thermophilous forests. (C) 1998 INQUA/Elsevier Science Ltd. All rights reserved.