The first experiments on animal regeneration, in the 18th century, played a major role in the evolution of biological thought and gave birth to the science of Experimental Zoology. Since then, regeneration, a field of active investigations related to reproduction, differentiation, growth, metabolism and morphogenesis greatly contributed to the understanding of biological processes. Apart from a brief historical review and an account of regenerative phenomena in various animal groups, this article deals with recent findings and trends of research in the field. Molecular, genetic and cellular aspects of regeneration are considered mainly in the paradigm of the amphibian limb. The significance of morphogens (e.g. retinoic acid), homeoproteins, antigens, growth factors and other molecules is considered; theoretical models (e.g. positional information) and the relationship of regeneration to tumorigenicity are also examined. It appears that organ regeneration is a well orchestrated system of spatiotemporal interplay of molecules and cells, highly coordinated and with obvious adaptive value. What is still eluding our research is the Ariadne’s clew leading to the director of this orchestra.