An understanding of the hydrobiology for the normal functioning of biotic and abiotic factors is essential for the exploitation of aquatic resources and for the better management of the estuary. It is with this idea, the present study has been made to detail the environmental characteristics of Kadinamkulam estuary. It is a shallow backwater with the mean depth of 2.11 ± 0.27m. Sewage and retting materials were the main sources of pollution. The physico-chemical parameters analyzed in the present study include temperature, pH, salinity, alkalinity and dissolved oxygen. The toxic gases hydrogen sulphide, ammonia nitrogen and nutrients viz. nitrite-nitrogen, phosphate phosphorous and silicate-silicon of water samples were analyzed. The sediment was also analyzed in relation to organic carbon, total nitrogen, total phosphorus and trace metals such as copper, lead, manganese nickel and zinc. From the present study the parameters which are unsuitable for the healthy environment increases during pre monsoon due to concentration of pollutants. The winter season showed less nutrients and trace metals with high dissolved oxygen. The distributions of these were also dependent upon the location of the station. Copyright © Enviromedia. © 2008 Elsevier B.V., All rights reserved.