The Multicenter Evaluation of In Vitro Cytotoxicity (MEIC) is an international programme organised by the Scandinavian Society for cell Toxicology. The program started 1989 and will end in 1994. As an update of the original, detailed 1989 description of MEIC, this paper presents the actual aims, main assumptions, design and evaluation methods of the study. The present status of the testing activities and the preliminary evaluation performed are accounted for. Finally, the prospects of MEIC are discussed. The study may contribute to a future reduction of animals in toxicity testing. Results of the study could also lead to a more rationale science of toxicology, based on the reactions of cells and cellular receptors, rather than on the reactions of animals.