The cytotoxic effects of the first ten chemicals from the Multicenter Evaluation of ln Vitro Cytotoxicity (MEIC) programme on the fibroblast-like R1 cell line, derived from rainbow trout (Oncorhynchus mykiss), were measured by using three endpoints: cell attachment (24-hour exposure, crystal violet protein stain); cell viability (24-hour exposure, neutral red uptake cytotoxicity assay); and cell growth (144-hour exposure, crystal violet protein stain). The results were compared with published MEIC toxicity data from fish and mammalian cells, and from ecotoxicity tests with bacteria, invertebrates and plants by using multivariate statistical techniques. For eight of the ten compounds under consideration, a high degree of correlation in toxicity ranking between the various bioassays was observed, irrespective of the test systems or endpoints utilised. This similarity might be explained by the basal cytotoxicity concept. The 20% dissimilarity of the results, however, indicates the influence of test system-specific or endpoint-specific sensitivities.