The study relates to the ichthyofaunal resource of Era Kopili Beel of Karbi Anglong District, Assam, India. A total of 47 number of fish species including 4 exotic fish species belonging to 33 genera under 18 families from 6 orders is recorded from the present study. Among the recorded fish species no species is recorded as vulnerable, 1 species is data deficient, 1 species is endangered, 3 species is lower risk-near threatened, 38 species are lower risk-least concern and other 4 species are not evaluated. The different families recorded are Belonidae, Cyprinidae, Cobitidae, Badidae, Ambassidae, Anabantidae, Channidae, Gobiidae, Osphronemidae, Nandidae, Bagridae, Clariidae, Heteropneustidae, Schilbeidae, Siluridae, Synbranchidae, Mastacembelidae and Notopteridae. The taxonomic study shows that Cyprinidae is the most dominant family with 17 number of species contributing about 36.17% of the 18 recorded family from the present study followed by Channidae (8.51%). The study also reveals that the Era Kopili Beel is rich in fish diversity.