The fish diversity is a good indicator of health of aquatic ecosystem and represents the balanced ecosystem. The present study was conducted for a period of one year from January 2017 to December 2017 in Durgadahalli Lake which is located in the north-east of Tumakuru district, at a distance of 15 km from Tumakuru city of Karnataka. It lies at 13° 13' 56" N latitude and 77° 25' 30" E longitude. It receives water mainly from rain fall at an average of 620 mm and by Jayamangalli river. In recent years due to varied ecological conditions and impacts of human activity have increased variations in aquatic ecosystem. Hence, the present report on fish diversity is of its first kind in Durgadahalli lake. A total of 10 species of fishes belonging to 09 genera, 03 families and 02 orders were recorded from the lake. The order Cypriniformes (80%) was found to be dominant followed by Perciformes (20%) among fish assemblage. All the fish species recorded were of commercial importance.