For a number of years, investigators have recognized that humans potentially are exposed to large numbers of genotoxicants. Many efforts have attempted to validate various short-term bioassays for use as rapid, inexpensive screens for genotoxicants--especially carcinogens. Salmonella mutagenicity as an indicator of potential carcinogenicity is examined by comparing published (and when possible, evaluated) Salmonella results with the evaluated Gene-Tox animal carcinogen data base. The Salmonella bioassay does especially well in those cases where the level of evidence for carcinogenicity is the strongest. Analysis shows that except for special classes of compounds, the plate-incorporation protocol and the preincubation protocol are equally efficient at detecting mutagens. The paper also demonstrates how validation values (sensitivity, specificity, etc.) vary with chemical class. Overall, the analysis demonstrates that when used and interpreted in a meaningful chemical class context, the Salmonella bioassay remains extremely useful in identifying potential animal carcinogens. (Copyright (c) 1988 Elsevier Science Publishers B.V.)