The territorial behaviour of the hunters-gatherers groups in the North-eastern side of Italy and in the neighbouring areas from the middle Pleistocene to the Early Holocene is analysed here. The data were collected through the study of the site distribution and typology, of the economical data, and of the raw material procurement areas. It results that humans did never frequent intensively the Caput Adriae, and that their mobility was affected by a strong environmental determinism; consisting mostly in climatic and geographical constraints. The sea-level lowering of the cold phases caused the emersion of a plain in place of the Northern Adriatic Sea, “displacing” the area from a coastal to an inner continental position, and greatly changing the availability of food resources. As a consequence the area was almost completely abandoned; only small groups of Neandertals visited this region for short and wide-range raids during the early Upper Pleistocene. During warmer periods, the movements were short to medium range, and limited to the strip between the coast and the mountains; short trips for food and raw material procurement to nearby areas were also common. In this framework, the Mesolithic groups intensificated the extraction of food resources by increasing the short-range mobility within a small territory.