The application of systems analysis techniques identified a number of key factors which will determine future developments in the Gambian livestock industry, with especial reference to traditionally managed trypanotolerant, N'dama cattle, and the importance of tsetse and trypanosomiasis. Different components of the analysis repeatedly identified the following key factors: human population growth; declining rainfall; loss of tree cover; trends in land-use including increased areas under cultivation, reduced fallowing and reduced access for grazing; livestock numbers; prices for groundnuts (the main cash crop) and cattle; and indicators of national wealth reflecting cash available to invest in livestock or to purchase livestock products. In many areas tsetse and trypanosomiasis appear to be in decline as a result of habitat destruction but they are likely to persist in others where trypanotolerant animals face a high risk of trypanosomiasis infection and active control may bring significant benefits. Several of the identified trends raise doubts concerning the long-term sustainability of traditional grazing on common land, although improved, intensive management strategies can do much to alleviate these problems.