The piscean diversity or fish diversity of any water body is the reflection of its physical status. The present study deals with the fish diversity of Manoharsagar Reservoir. A total of 31 species of fish belonging to 12 families and 5 orders were recorded. The present investigation has done during the period July 2016 to June 2017. The present study reveals that the reservoir enriched with good biodiversity of fish indicates healthy physical status of it. In the present paper the economic importance of the fish and fisheries is discussed. Most of the species of fishes recorded were found throughout the year.