The establishment and management of protected areas are costly, and nature conservation authorities especially in developing countries face huge problems in financing these costs. While it is well established that effective biodiversity conservation increases the attractiveness of a protected area for visitors, the management effectiveness in many parks suffers from the lack of funds. This paper deals with the willingness to pay of international visitors for an increase of admission fees in order to cover management costs in a prominent national park in Nepal (Langtang national park). The results of the on-site survey indicate that international visitors would be willing to pay entry fees that are much higher than those currently charged (local visitors are currently exempt from paying entry fees). Compared to the existing entry fees of 30 USD, visitors would – on average – be willing to pay about 64 USD per visit. An econometric estimation of the determinants of WTP shows that visitors whose experience in the park is above average are also willing to pay higher entry fees. In addition, visitors would also accept temporary or spatial restrictions of access if these policies would improve the conservation of biodiversity. With respect to conclusions regarding the management of protected areas, the study clearly shows that entry fees of international visitors may be significantly increased in order to broaden the financial basis for effective and efficient biodiversity conservation with the ultimate goal of sharing the benefits of conservation with the local population.