Recent investigations of prefarming adaptations during the Mesolithic period in early Holocene Europe have led to significant revision of traditional views. A number of innovations and changes occur, particularly toward the end of the Mesolithic, that permit this time to be described as both dynamic and extraordinary. Permanent settlement and the use of domesticated animals, exchange, and, perhaps, cultivated plants and monumental tombs characterize a number of later Mesolithic adaptations. The transition to the Neolithic is now regarded as the result of in situ developments in most areas of Western Europe, as Mesolithic groups slowly adopted pottery, cultigens, and other characteristics of farming villagers. In this paper, questions regarding chronology, nomenclature, and the definition of terms are addressed initially. Changes in European environments at the close of the Pleistocene and during the early postglacial are considered in terms of major impacts on human adaptation. The central focus of this study is a survey of the Mesolithic in Ireland, Britain, the Netherlands, Belgium, France, Portugal, Spain, and Italy. Recent research projects in these areas are discussed in terms of new approaches and results. An overview of developments in these countries is also presented, emphasizing the transitions from the Paleolithic and into the Neolithic. Concluding remarks address future directions in Mesolithic research.