Water borne diseases are viral, bacterial, and parasitic diseases which use water as a common means of transmission. Water borne diseases are caused by water that has been contaminated by human or animal wastes and include diseases such as cholera, typhoid, shigella, polio, meningitis and hepatitis A&E. A Study to assess the knowledge on waterborne diseases among general population at Maraimalai Nagar. Objectives: To assess the knowledge on water borne diseases among general population. To associate the knowledge on water borne diseases among general population with their demographic variables. Methodology: Quantitative research and descriptive design was adopted to the study. A total of 100 general public were selected by non- probability convenient sampling technique. The samples were interviewed by self - prepared interview schedule. The tool had two sections. Section - A Consists of demographic variables and Section -B Consists of 21 questionnaires to assess the level of knowledge on water borne diseases. The collected data analyzed by using descriptive and inferential statistics. Results: The result of the study reveals that among 100 general public, 23 (23%) people had adequate knowledge on water borne diseases, 49 (49%) people had moderately adequate knowledge on water borne diseases and 28 (28%) people had inadequate knowledge on water borne diseases. CONCLUSION: Most of the people had moderately adequate knowledge, so investigator felt the need to help them to improve their knowledge through an educational approach by providing health education pamphlet.