This paper details the approaches and tools developed at ICLARM to contribute to the sustainable management of fish as a food resource in the Mekong River Basin. Multiple partnerships have been established in order to gather, compile, analyse and compare existing data on fish resources. Core contributions from Mekong River Commission projects have been supplemented by additional data and experiences from a large range of sources. Matching data from different origins allowed for i) the development of hydrological and flooded vegetation models, and ii) the comparison of basinwide trends in fish migrations and catches. The tools developed also include FishBase, a database on fish taxonomy and biology. The information available in FishBase can be used to determine functional guilds of fish based on their biological characteristics. A variety of hydrological and environmental factors that influence fish production have been identified. This has led to the development of a qualitative Bayesian model of Mekong fish resources. The development of this model is proposed as a tool for promoting discussions and interactions between regional institutions, national and local government agencies responsible for fisheries and environmental management in the Mekong Basin.