In 1988, three symposium were held on the ''Neolithisation'' of Western Europe, in Strasbourg, Liege and Brescia respectively. In this article, the author attempts a synthetic evaluation of the various contributions, listing the problems revealed by a new understanding of the process. The classical model opposing a Danubian Neolithic colonisation and a Mediterranean progressive acculturation has lost its simplicity. Generally speaking, it now seems that colonization occurred in both regions, amidst Mesolithic populations without an internal trend towards food production and sedentism. Several cases of interaction have been detected between the hunters and the newly arrived colonists, in an environment still little transformed by the new production techniques. The period of contact seems to have been locally quite short (3 to 7 centuries), although on the European scale this process lasted nearly two thousand years. The two Neolithic currents were in contact quite early due to the quick expansion of the Mediterranean cultures. In this perspective, we can admit the existence of important acculturation processes of the Mesolithic hunters in the contact zone between the two currents: Brittany, Paris basin, Jura, Po plain, Dalmatian coast. This synthesis raises three new issues: the significance of the term ''Neolithisation'', the typology of the societies involved, and the relative proportions of local and alien populations in the demographic pattern of prehistoric Europe. The answer to these questions depends on the establishment of a new historical scenario, based on a chronological scale of calibrated C-14 dates, and on a better understanding of the discontinuities in the evolution of the lithic industries.
