This study evaluated the production and quality of biogas (CH₄, H₂S) and the quality of the effluents (DQO, DBO), using cattle manure dissolved in water and vinasse as a supplement in biodigesters. The study was conducted with four different treatments (0 %, 30 %, 40 % and 50 % vinasse replacing the water) and three repetitions for each treatment, for a total of 12 scale model biodigesters. The control sample (0 % vinasse) produced the highest amount of biogas. The highest concentration of CH₄ in the biogas was generated with 40 % and 50 % vinasse treatments. The control sample was the only one generated H₂S in the biogas. For all treatments there was a reduction in the concentrations of COD, BOD and total solids in the effluents. However, these reductions were not sufficient for the effluents to be discharged into natural waterways.