The Middle Paleolithic site of Cuvilly was excavated prior to the construction of a large interconnected network of gas pipelines. 4960 square metres were completely stripped. The archaeological level was eroded in the eastern part of the excavated area, and well preserved in the western part. The sedimentary sequence is fairly compressed, and thus rather difficult to interpret. The observations made during the excavation , the micromorphological study and the comparisons with the local stratigraphical sequences of reference enabled the sedimentary unit with artefacts to be attributed to the isotopic 5c  substage (Brorup). The archaeological level, comprising 404 artefacts, yields a technological spectrum comparable to that of lithic industry deposits of the same period. Cuvilly is thus an important milestone in the research into the way Northern Europe was populated during the Pleistocene. Indeed, in the present state of research in the Nord – Pas de Calais –Picardie region, only seven sites have been clearly attributable to this intermediary stage. Traduction : Margaret & Jean-louis CADOUX