AbstractTo evaluate the genotoxicity of hospital wastewater, we drew up a simplified protocol based on two well‐known tests: the SOS chromotest and the Ames fluctuation test. Three concentrations of wastewater samples were directly tested without extraction or concentration. By fixing three significance levels in genotoxicity response for each test, we could classify the samples in five categories ranging from nongenotoxic to highly genotoxic. This simplified classification thus constitutes an invaluable help in making the nonscientist public aware of the genotoxic risk of hospital wastewater and can be applied in a screening approach to chemicals in the environment. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 141–146, 2006.