The disposal of untreated effluents directly affects the water quality of the receiving medium, which can cause damage to the aquatic ecosystem and to human health. Therefore, the objective of this study was to analyze the toxicity and the physical and chemical parameters of raw and treated effluents of a meatpacking and a textile plant, in order to evaluate the effectiveness of the treatment. Thus, cytotoxic tests with Allium cepa L. and the immobility/mortality test with Artemia salina L., besides the physical and chemical tests of pH, ammoniacal nitrogen, oxygen demand, total solids, chlorides and alkalinity were used. The immobility/mortality test with Artemia salina L. revealed the absence of dead organisms in the tested low concentrations of raw and treated meatpacking and textile effluents. However, the highest concentrations of raw meatpacking effluents (50 % and 100 %) and treated meatpacking effluents (100 %) caused the mortality of organisms. Raw and treated textile effluents were statistically toxic only at the highest concentration evaluated (100 %). Furthermore, the raw and treated effluents of the meatpacking and textile plants were not cytotoxic in the test with Allium cepa L. The results of the physicochemical analyses proved the effectiveness of the treatment of the meatpacking effluents in terms of diminished pH, ammoniacal nitrogen, chemical oxygen demand, and total solids. And the raw effluents from the textile plant also exhibited a reduction in pH, chlorides, alkalinity and total solids. The treatments were effective for these effluents, but still had a toxic effect on A. salina. Thus, it is indicated that additional treatment should be carried out in the textile and meatpacking effluents, emphasizing the importance of adequate treatment systems to prevent environmental harm and public health problems.Palabras clave: Allium cepa L., Artemia salina L., efluente de empacado de carne, efluente textil, toxicidad RESUMEN La liberación de efluentes no tratados afecta directamente la calidad del agua del medio receptor, pudiendo traer perjuicios al ecosistema acuático y también a la salud humana. Por lo tanto, el objetivo de este estudio fue analizar la toxicidad y los parámetros fisicoquímicos del efluente con y sin tratamiento de una planta textil y una empacadora
