An attempt has been made to evaluate the water quality of supplemented and ground water in Tirumala and Tirupati, Chittoor District, Andhra Pradesh, India. The Tirumala and Tirupati are the most popular pilligramage and education areas in Andhra Pradesh. Twelve areas of Tirumala and Tirupati have been selected, where the peoples are used supplemented and groundwater for drinking purpose, and the water samples were subjected to systematic analysis with a view to understand the potability of drinking water sources. The values obtained for different parameters have been compared with the standard values given by ISI/ICMR/ WHO and the variations were notable for the parameters like electrical conductivity, total dissolved solids, total hardness and nitrates for few samples. Medical survey has been carried out to study the harmful effects on the society due to these four parameters at the areas - Tiruchanur, Renigunta and Karakambadi.