This study inspects the impact of anthropogenic activities on groundwater quality; this was achieved by determining the concentration nitrate (NO3-) in the groundwater samples of Sagar town and its surrounding villages. Thirty seven (12 from villages and 25 from town) groundwater samples were collected and were analyzed to determine the water quality characteristics with a view to ascertain the level of contamination and suitability for human consumption during pre-monsoon (May, 2010) and post-monsoon (December, 2010) periods and were compared with the standard values given by WHO (World Health Organization). An analysis of these water samples revealed that some groundwater samples were showing a high concentration of nitrate exceeding permissible limit of WHO (50 mg/l), due to the anthropogenic activities in the study area which is hazardous to health. This study will be helpful in solving the problem related to drinking water in the study area.