A study was conducted to evaluate the quality of drinking water samples from the four different drinking water sources namely open wells, Bore wells, can water and tap water from 37 wards of Kavali Municipality, SPSR Nellore district, A.P. The microbiological parameters such as total viable count of bacteria, total conidial spores were carried out. The physico chemical parameters are using standard method. It was found that the open well water was contaminated in almost all the wards of the municipality. The microbiological contamination of drinking water is in this order. Open well water > Municipal tap water > Bore water > Can water. The results shows that the total viable count of the Open well water is highest (95 × 104 bacteria / mL) and lowest in can water. The total conidial spores are also high in open well waters (10.75 × 104 spores / cm). Total plate and coliform count revealed that 82.6 % and 92.4 % of drinking water samples found to cross the WHO guideline value for drinking water. Total viable count was by pour plate technique while Most Probable Number (MPN) counts were by the multiple tube fermentation technique. The pH (at 25oC) ranged from 6.1 to 8.33 for the untreated raw water samples while temperature ranged from 28 to 30oC while the turbidity of the water and waste water samples ranges from 0.08 to 1.00. The total viable counts for all the water samples were generally high exceeding the limit of 1.0 × 102 cfu/mL for water. The MPN count ranges from 9.3 to 44 MPN/100 mL. The fecal coliform counts on EMB agar plate ranged between 5 and 48 cells, also exceeding the standard limit for water. The Isolated organisms were identified to be organisms namely Escheichia coli, Pseudomonas aerugixnosa and Proteus vulgaris species.