Man and environment have always been strictly connected, one influencing the other, but the character of this relation changed over time and space. Whilst during the first phases of the human evolutionary history man was highly dependent on environmental resources, over time many societies have changed this relationship and the influence of the man on environment became stronger and stronger. Focusing on Sicily, the first phases of human occupation can be dated to Late Pleistocene and since then human behaviour has been influenced by the natural resources provided by the island. Nevertheless first humans also affected the ecology of the island by the extensive exploitation of resources and later with the introduction of mammals from the mainland. In this communication we consider the relationship man-environment in Sicily during the Late Pleistocene and the Early Holocene by an interdisciplinary study of vertebrate and invertebrate fossil remains from two key archaeological sites: Cala Mancina Cave (San Vito lo Capo, Trapani) and Oriente Cave (Favignana Island, Trapani). Whilst the first deposit provides a very good documentation for a short interval of time, with the oldest date at 9332±60 BP , the second one spans a longer time, dating from 12,132 BP to 7040±55 BP, and records the transition from Upper Palaeolithic through Mesolithic to Early Neolithic and thus the Late Pleistocene-Holocene transition. From both sites large mammal and marine mollusc remains provide detailed information about the diet. On the other hand small mammals and terrestrial molluscs provide valuable insights into palaeoclimatic and palaeonvironmental conditions in the Central Mediterranean basin at the time of sites formation.