Knowledge of organic fluxes from rivers to oceans is essential for calculating their possible sinks and sources. It has been realized in recent years that estuaries play an important role in modifying the river inputs to oceans. The organic contents entering the system through various sources may associate with the sediments particles either by absorption are gradually sink with sediment or they may get released when mixed with marine water due to altered physico-chemical environment. For the present study three different estuaries around the south west coast of India in the Trivandrum district were selected. They are Kadinamkulam, Veli and Poonthura backwaters. From each estuary three different stations were fixed for the collection of sediments. The study was carried out with the monthly collection for a period of one year (April 2004 to March 2005).Organic carbon; total nitrogen and total phosphorous were analyzed in the collected sediments using standard procedure. Seasonal and mean variations in the concentration of the C N P were observed and presented. The distribution of C N P observed from the present study reflects that the seasonal fluctuation of the organic contents was due to the waste discharges in different rates at different seasons in to the estuary. Copyright © Enviromedia. © 2008 Elsevier B.V., All rights reserved.