Water is one of the naturally occurring vital constituent of the ecosystem which supports all life activities. Fresh water is a source of drinking water and is getting polluted by the discharge of domestic sewage, industrial effluents and anthropogenic activities. Analysis of Physico-Chemical parameters of Siddapura lake Tumkur district was done during the period of July-2015to December-2015.The water samples were collected on the monthly basis from three sampling sites. The analysis was carried out for the parameters like Temperature, pH, Electrical conductivity, Turbidity, Chlorides, Nitrates, Sulphates, Phosphates, and Biological Oxygen Demand (BOD).