This study on the aquatic coleopteran diversity in rice revealed 24 species under 18 genera and 5 families in the irrigated rice ecosystem of Pandit Jawaharlal Nehru College of Agriculture and Research Institute (PAJANCOA & RI), Karaikal, Union Territory of Puducherry. The study was conducted during kharif 2019 and rabi 2019-2020. Berosus indicus was the dominant species in both the seasons. Dytiscidae (47.89%) and Hydrophilidae (49.23%) were the abundant families. Species diversity was maximum in kharif 2019, while species richness was maximum during rabi 2019-2020. Dytiscidae exhibited a significant negative correlation with water temperature, while Gyrinidae, Hydrophilidae and Noteridae showed significant negative correlation with pH, electrical conductivity, air and water temperature, and positive significant one with relative humidity. Multiple linear regression indicated that all the physico-chemical characteristics together were responsible for significant variation on the occurrence of Dytiscidae (92%), Gyrinidae (51%), Hydrophilidae (60%) and Noteridae (59%).