Groundwater quality plays an important role in conservation of water resources not only for the present generation but also for the future generation. Each and every harvest season witness excessive use of pesticides and fertilizers in the agricultural fields. During a monsoon season these potential hazards leaches into the soil and mixes with the groundwater. This paper aimed at studying the Physicochemical parameters of pre-and post-monsoon groundwater quality of Velliangadu Village of Coimbatore district in the state of Tamil Nadu to reveal the water quality parameters before and after a monsoon season. The Physico-chemical parameters considered for drinking water like pH, electrical conductivity, total dissolved solids, total alkalinity, total hardness, dissolved oxygen, chlorides etc. were analysed for pre-monsoon and postmonsoon groundwater samples collected from different areas and compared.