Abstract: The fishes are one of the most important vertebrates, provide rich protein sources for human and several animals and important elements in the economy of many countries. Fish diversity of river essentially represents the ichthyofaunal diversity and their abundance. Rivers conserve a rich variety of fish species which supports the commercial fisheries. Keeping in the view, the diversity of fish fauna of the Birupa River in Choudwar Town, Odisha, India, has been studied from the period January 2018 to March 2018. The aim of the study was to explore the fish fauna of Birupa River in the course of an investigation, 4 sampling sites were selected viz. Birupa Barrage, Birupa Anicut on Birupa river, Jora fishing site, Birupa Fish Market, Choudwar. The total 36 fish species belonging to 25 genera, 16 families and 9 orders were recorded. Cypriniformes constituting 15 species, followed by order Siluriformes constituting 6 species, Perciformes 4 species, Anabantiformes 4 species, Clupeiformes 2 species, Osteoglossiformes 2 species and order Mastacembeliformes, Cichliformes and Tetraodontiformes constituting 1 species each have been recorded. The Cyprinidae family is dominant followed by Channidae. As no attempt had been made in the past to explore the ichthyofaunal diversity of this region. All the species reported in present investigation are reporting first time under mopping survey programme.