The ground water quality in Coimbatore city along the Noyyal river during pre-monsoon and post-monsoon seasons in 2005 is discussed in this paper. Water samples were collected from 12 wells on either side of the river. The physico-chemical analysis of the collected samples was carried out for the parameters, such as pH, total dissolved solids (TDS), electrical conductivity (EC), total hardness (TH), alkalinity, calcium (Ca2), magnesium (Mg2), chloride, sulphates and sodium.