This paper analysed the spatial-temporal variations of surface water quality of the Pallikaranai wetland, located in the region known as Chennai City. An extensive study pertaining to seasonal variations in nutrients, dissolved carbon, dissolved gases and heavy metals in surface water was studied at 16 locations of Pallikaranai wetland during three seasonal cruises from March 2010 to December 2010. GIS and statistical techniques such as interpolation method (IDW), Pearson correlation and principal component analysis (PCA) were applied to evaluate the spatial pattern and variation in water quality of Pallikaranai wetland and to identify pollution sources. The results revealed that there is a remarkable seasonal variation in the analysed parameters which are attributed to the natural sources (monsoon) and anthropogenic activities. PCA resulted in three factors explaining 73.8% of the total variance. Factor 1 exhibited a high correlation with environmental parameters, nutrients and organic carbon representing the influence of seasonal runoff. Factor 2 envisaged heavy metal pollution results from anthropogenic activities. Factor 3 explored moderate correlation with SPM and nutrients.