A survey of aquatic Oligochaeta was conducted at Thiruvallur, Chennai, Kanchipuram, Villupuram and Nilgiris districts of Tamil Nadu from October 2015 to June 2016. Eleven taxa were recorded from a total of 922 specimens examined, eight of them were identified to species level. Five naidids identified during the present study: Branchiodrilus semperi, Dero dorsalis, Dero digitata, Dero indica and Dero zeylanica, and six tubificid taxa Branchiura sowerbyi, Tubificidae sp. 1, Tubificidae sp. 2, Tubificidae sp. 3, Limnodrilus hoffmeisteri and L. udekemianus. Dero dorsalis constitute the first report for Kanchipuram district. A DNA barcode sequence (GenBank accession no. MF125273) of the commercially important Limnodrilus hoffmeisteri, commonly known as ‘Tubifex worms’ in Chennai, was obtained and compared with other published COI sequences from that morphospecies from around the world.