The objective of this study was to develop a system capable of evaluating the quality of the water consumed by an urban population using fuzzy logic. The set of factors to be analyzed were total coliforms, fluoride, free residual chlorine, turbidity, and apparent color. The factors selected as indicators of water quality and the system rules were modeled using the INFUZZY tool with help from specialists in this area, using a Great, Good, Acceptable or Inappropriate quality classification. 47 water quality analyses were applied. The results showed that 57.44% of the samples had a water quality classified as Great, 2.12% as Good, 2.12% as Acceptable, and 38.29% as Inappropriate. For each sample, results were in agreement with the evaluated parameters.