Assessment of water pollution and its effect upon river biotic communities and human health is indispensable to develop control and management strategies. The aim of this work was to ascertain the biotoxicity of water pollution in samples from industrial effluent discharge areas of Tucumán, Argentina by means of biological tests. Chemical characterization of the water pollution was verified by measuring dissolved oxygen concentration or levels of suspended matter and salts. Genotoxic/mutagenic potential was determined using Allium anaphase-telophase and Ames/Salmonella tests. All samples were phytotoxic and genotoxic for Allium roots. Micronucleus and anaphase aberrations were observed, but they did not show mutagenic effects on Salmonella typhimurium, TA98 and TA100 strains with and without metabolic activation (S9). Our results show the importance of testing industrial effluents by chemical methods and complementary biological tests to optimize the control policy on these environmental samples.