This study was conducted in the urban area of Khamis Mushait City, Aseer Region, and Saudi Arabia. A total of 50 samples of drinking water were collected from private selling sites of unbolted water in the urban area of Khamis Mushait city. Physicochemical parameters such as pH, total dissolved solids (TDS), and electrical conductivity (EC) of water samples were measured using standard methods to assess the quality of drinking water. The pH values of water samples ranged from 6.56±0.1 to 8.5±0.49, TSD changed from 104.7±0.28 to 202.4±1.7 mg/liter and EC from 163.6±0.45 to 316.3±2.61 µS/cm. The previous results indicated that all physicochemical parameters are within the permissible limits of WHO (2011) for drinking water quality. The bacteriological examination of water samples included the most probable number (MPN/100 ml) of coliforms, E.coli and Pseudomonas aeruginosa. The results showed that E. coli bacterium was not detected in all samples, while total coliform group was found in 7 samples out of 50 samples analyzed (14%) and Pseudomonas aeruginosa was found in 24 samples out of a total of 50 samples (48%). Furthermore, this study has revealed that about 54% of the water samples collected from private selling sites is incompatible to the World Health Organization (WHO) standards for drinking water quality.