One of the important environmental issues is the quality of surface waters in the world. Poland belongs to countries with a low quality of the inland waters. The sanitary condition of the five water reservoirs of south-east Poland was analyzed. Water and sediment samples were incubated on the selective and/or differential media. High concentrations of many common and pathogenic microbial indicators were shown in those samples. Those reservoirs are used by people, especially during summer. Because of the high epidemiological risk, detailed analysis of all inland waters should be performed routinely.