Nepal is blessed with plenty of freshwater bodies and rivers constitute one of the most abundant freshwater resources. There are different kind of studies in many rivers of Nepal, however studies on fish assemblage has been a less studies aspect. Indrawati River in particular has not been intensively studied for its aquatic biota such as fish. Therefore, we hope that this report helps to explore one of the unfolding realities on fish assemblage in one of the important river basins of Nepalese mountain. This kind of research needs inputs and support from wide variety of people, both skilled and non-skilled. The investigators would like to acknowledge many people who helped us during our fieldtrips. We owe the help of our ‘core fishing team’throughout the project period. The skilled assistants include Arun Rana, Bikash Gurung, Kumar Khatri and Khadak Rokaya. The students who helped us during the field work as well as data compilation are Ashish Gurung, Damodar Dhital, Rakshya Kayastha, Rajendra Bhandari and Tanuja Shrestha. All these names are mentioned alphabetically.