In the present study, sediment samples were collected from different locations and diverse environments around Chennai city to evaluate the environmental conditions and the health of the water bodies. The grain size analysis of the sediment samples reveals that sand is the dominant fraction deposited in highenergy coastal environments followed by silty sand, sandy silt, while as the sediment samples of Cooum River and fresh water lakes and Buckingham canal show the dominance of silty clay and clayey silt respectively. The C/N ratio of the sediment samples indicates in situ source of algal organic matter, except Cooum River, while the confluence of the Cooum River to the sea and the Buckingham canal exhibits dominant terrestrial source of organic matter. Significant positive correlation of clay with TOC, C/N ratio signifies strong binding of these elements with finer clay particles. Predominant occurrences of diatom species such as Cyclotella striata, Navicula and Nitzchia linearis in the water bodies of Chennai shows high organic pollution caused by anthropogenic influences.