The indiscriminate dumping and release of wastes and hazardous substances from various sources in to Uppanar River might lead to water quality deterioration which could be considered as a potential source of stress to biotic community as well as human beings. The objectives of the present study is to investigate the seasonal (monsoon, post monsoon and summer) variations in physico-chemical characteristics of Uppanar River in three sampling stations for the period of one year from July 2013 to June 2014. The results of the parameters determined include temperature, turbidity, pH, dissolved oxygen (DO), total dissolved solids (TDS), total hardness, total alkalinity, calcium, magnesium, chloride, ammonia, nitrate, nitrite, sulphate, phosphate and iron showed seasonal variations among stations. During summer the values were higher in three stations followed by monsoon and post monsoon seasons. The present results indicated that the values of all the observed parameters were not within the permissible limits of WHO standards except dissolved oxygen; this might be due to continuous mixing of water. According to our observations, station III was more polluted, station II moderately polluted and station I was less polluted. This might be due to continuous discharge of industrial and municipal wastes in to Uppanar River.