Quality drinking water is essential for life. Contaminants such as, heavy metals, organic compounds, bacteria and viruses have polluted water supplies as a result of inadequate treatment and disposal of waste from humans and livestock, industrial discharges, and over-use of limited water resources. This study was conducted to assess constraints in quality management, determine contamination level of contaminates and analysis the physicochemical properties of river water and potable water. Samples were collected from different sites of the Baro River and Gambella town during spring season. The important water quality parameters such as: Color, Odor, Temperature, pH, TSS, TDS, TS, BOD, COD, DO, Turbidity, EC, Total hardness, contents of major ions(Fluoride, Chloride, Sulphate, Nitrite, Calcium, Potassium, Magnesium, Sodium) and some heavy metals were analyzed. Assessment of the water samples for pollution is made by comparison the values of all the physico-chemical parameters with the corresponding standards prescribed for drinking water by different national and international standards specially (WHO) World Health Organization standard for drinking water. Several analytical techniques including titration, flame photometer, Atomic Absorption spectrometer and multi water quality checkers were used to determine the quality of the water in the areas under investigations. The findings indicated that most of physicochemical parameters: odor, temperature, total hardness, TDS, TS,, both cations and anions, DO,COD, heavy metals for all samples were within the permissible limits of WHO for drinking water. Whereas, color, EC, TSS,BOD, temperature and the values of total turbidity of samples from Baro River were found beyond the permissible limits of WHO.