The study of plant diversity within national parks and wildlife reserves is important for the effective habitat management of wildlife and their habitat. This paper describes the floral composition, local distribution and use of plants in Royal Shuklaphanta Wildlife Reserve in southwestern Nepal based on a survey conducted from September 1997 to December 1999. The study included the collection and identification of flowering plants, and interview with local people about the several uses of the plants collected. The area has different habitat types such as forests, grasslands, floodplains, lakes and marshes, and is famous for a number of wildlife species. Altogether, 562 plant species belonging to 102 family and 375 genera were recorded. Seventy-four species are newly recorded in the western lowlands of Nepal and among them, 26 species are new additions to the flora of Nepal. Twenty-seven species were found locally rare within the reserve. Local people use 208 species for various purposes. Royal Shuklaphanta Wildlife Reserve is rich in plant diversity, but its management measures may be needed to maintain species richness within the reserve.