The relationship between water quality and the watershed occupation in the Pitangui River was investigated by physical-chemical and biological parameters.For this, samples of freshwater were collected for 12 months.After the analysis the quality indexes IQA B and IQA PVA were applied.Even though these indexes have a subjective nature, they allow us to publish the experimental results on a simplifi ed way.The IQA B , which is associated with the water potability, showed an acceptable quality, however, the value obtained for IQA PVA indicated low quality and risk to aquatic life.