River systems are the primary means for disposal of waste, including effluents and pesticides from industries and agriculture. The most common critical problem in developing countries is improper waste management caused by various human activities. Water quality characteristics of aquatic environments arise from a multitude of physical, chemical, and biological interactions. The geochemical characteristics of water bodies like rivers, lakes, and estuaries are continuously subjected to a dynamic state of change. In the present study, seasonal variations in physic-chemical analysis of water sample in the river water at various sites like Puthery, Ozhuginasery, Kothaigramam, Suchindram, Kakkamur south, Thamaraikulam north, Near the salt pan 2, Near the mangrove forest, Near the salt pan 1 and Sea mouth. The quality of Pazhayar river water is assessed through the assessment of parameters likepH, temperature, EC, TDS, TH, DO, BOD, COD, TA, SO4, NO3, PO4, Ca, Mg, Na, K and Cl. It was found that all the parameters were exceeding or below the permissible limit of standards (WHO and ICMR), so that the water in the study area is not suitable for drinking purposes. The pH and temperature were within the limit. The present study suggests the distinct nature of different bodies of river water; these distinct natures, however, depend on geographical location and seasonal variations. Seasonal variations were observed in the river, which was due to catchment characteristics and point or nonpoint sources of pollution.