Water quality index (wqi) was applied to study the quality and suitability of the borehole water for drinking purposes in afikpo south local government area. This was carried out by subjecting samples collected from eight locations by analyzing the physico-chemical parameters according to apha (1998) methods. Ten parameters such as the colour, temperature, ph, electrical conductivity (ec), total dissolved solids (tds), total alkalinity (ta), total hardness (th), dissolved oxygen (do), chemical oxygen demand (cod), ci-, so42-, no3-, na+, ca2+ and mg2+ were calculated for wqi . Results were presented in mean and standard error. The results obtained for wqi varied 121.57 – 186.68 for dry season and 101.59-167.82 for rainy season. The results indicate that borehole water in all the locations were unsuitable for drinking and need treatment. The deterioration of the water quality may have been contributed by the pollutants that were leached from the refuse dumps and agricultural practices which might have concentrated over a period of time and percolated into the aquifer.