Book excerpt: Eastern Africa’s livestock keepers face many challenges, not least the widespread prevalence of endemic diseases which both undermine animals’ productivity and increase livestock mortality. Tsetse- transmitted trypanosomosis causes significant economic losses, in particular in cattle. This study analyses these losses in a spatially explicit framework for the six tsetse-infested countries of the Intergovernmental Authority on Development (IGAD) region: Ethiopia, Kenya, Somalia, South Sudan, Sudan and Uganda. The cattle production systems of the region are diverse, ranging from pastoralism to agropastoralist and mixed crop-livestock farming. Some areas make extensive use of draught cattle or of high yielding crossbred dairy cows. Based on these features, twelve cattle production systems in the region were characterized and mapped. In these systems, the potential incomes from cattle production were modeled for a situation with and without trypanosomosis; the models looked at mortality, fertility, other productivity parameters and cattle population growth and expansion. The results of the analysis were used to generate a map of the potential benefits of controlling the disease. Estimates were then made of the costs of tsetse and trypanosomosis control using a range of techniques, namely: trypanocidal drugs; control or localized elimination of tsetse flies using insecticide-treated cattle or targets, aerial spraying and the sterile insect technique. The mapped potential benefits and mapped estimated costs were combined in order to produce a series of benefit-cost maps which illustrate what techniques are likely to be the most economically attractive in different areas of the study region. The suite of tools and economic analyses documented in this paper provide essential information to decision makers for comparing and prioritizing interventions in the region.