Freshwater resources are indispensable for the survival of all major life forms on earth but their quality has deteriorated due to various human activities. This study reports long term changes in the water quality of a Ramsar site, Lake Mansar located in the Indian state of Jammu and Kashmir. For this, four sampling sites were marked and various water quality parameters were analysed following standard methodology on a seasonal basis for one year and compared with three separate sets of published and unpublished data spanning a period of about 25 years. Results indicated that increased anthropogenic activities have certainly altered the water quality of Lake Mansar with deterioration in some water quality parameters. However, a comparison with standard values recommended for drinking water by international organisations suggested that all the parameters were within the recommended limits.1971, is an international effort to identify and protect the wetlands having ecological importance.One such Ramsar site located in lower Himalayas is lake Mansar that is socially and ecologically important but is under immense anthropogenic stress. Lake Mansar is a sub-tropical, rural closed lacustrine system without any surface channels and its main sources of water are subterranean springs and surface runoff. It is regarded a holy site from mythological period and thus holds a special position in the cultural and social sphere of the local population. It was given the status of Ramsar site owing to its ecological importance as it provides habitat and breeding ground for fishes and other aquatic life and many migratory birds visit the lake during winter. The lake also provides habitat to two important species of turtles, Lissemys punctata and Trionyx gangeticus, listed in CITES-IUCN Red list 2003 and very rare medusa, Mansariella lacustris. Owing to its domestic, religious, cultural Impact Factor (JCC): 4.6869 NAAS Rating: 3.58and recreational importance, the lake is being subjected to very high anthropogenic pressure. Performance of religious practices, increased tourism activities accompanied by developmental activities like construction of shops, restaurants, roads, boating station, view points, etc, adds to the pressure exerted by the local inhabitants. This increased pollution of