This study assesses the quality of ground water from eight different wells in Jazan city southwest of Saudi Arabia. Ground water samples were selected during July 2010 (dry season). Water samples were carefully collected for physico–chemical characteristics. pH, Electrical Conductivity (EC), Total dissolved solids (TDS), Cl, SO4, F, NO3, NO2, SiO3, total hardness and turbidity had been analyzed using standard procedures.  Selections of important cations which may be toxic in excess when present in drinking water were further discussed (Ca, Mg, Na and NH4). The chemical analysis of ground water samples show that not all samples comply with  World Health Organization Standards (WHO) for the parameters measured.  The bacterial parameters were analyzed for total count of bacteria, E. Coli bacteria and Fecal coliform. It was approved that no bacterial contamination present in the water samples. Results show that not all the water samples are safe for drinking purposes.