The concentrations of 60 polar pesticide residues were investigated in surface waters from eleven sites in two rivers, a pond and four drinking water wells in Coast region, Tanzania. The extracts were analyzed by Gas Chromatography-Nitrogen Phosphorus Detection (GC-NPD) and confirmed by high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS). Quantification of analytes was done by using the peak heights with two different m/z for each analyte. The compounds detected were atrazine, isoproturon and diuron. The highest concentrations of atrazine were 13 ng/l in drinking water, 16 ng/l in pond water and 172 ng/l in river water. The highest concentrations of isoproturon and diuron in river water were 18 ng/l and 12 ng/l, respectively. Atrazine was the most predominant pollutant in water. The results indicate that the source of contamination is due to the agricultural use of these pesticides in the nearby areas. The concentrations of atrazine, isoproturon and diuron in drinking water were far below the WHO guidelines for drinking-water quality.