The present study deals with ichthyofaunal diversity of Hiran-II reservoir, Gujarat. Sampling was carried out on monthly basis from January 2019 to February 2020. Total 23 species from 6 orders, 10 families and 19 genera were recorded during the present study. The range of water parameters such as temperature, pH, dissolved oxygen alkalinity and hardness were recorded and found suitable for fish production. Dominant family Cyprinidae with 12 species and 08 genera followed by Bagridae with 03 species 02 genera and other all families Claridea, Heteropneustidae, Cichilidae, Channidae, Gobiidae, Belonidae, Mastacembelidae, Poecilidae and Anguilidae contributed single species with single genera. Regarding conservation status out of 23 fish species 21 species least concern and 2 species near threaten. During month of December (post monsoon) highest fish diversity was found. Seasonal diversity indices such as Shannon-Wiener species diversity, Pielou's evenness, Margalef's species richness, were calculated based on the abundance of fish species to access the ecosystem health of Hiran-II reservoir. These studies will be help for the maintenance and regulation of Ichthyofauna and other aquatic ecosystem of the Hiran-II reservoir.