The challenges of humanitarian intervention in Sudan are representative for many situations in protracted crises. This research provided a rare opportunity to study the ' impact of a humanitarian program in chronic conflict, primarily based on the view of beneficiaries. Qualitative methods were chosen to capture perceptions and opinions of beneficiaries and of Medecins Sans Frontieres (MSF) local and international staff. The biggest obstacle in using a beneficiary based approach was at the same time an important finding of this study: the fact that the targeted communities are so little informed about the intervention, its aim, and the implementing agency, made it at times difficult to get responses to research questions. The main results of this study give indications on changes in health status and health perception and show multiple unintended impacts of an intervention in an area where there was previously little else existing apart from people's traditional means to survive. Considering the scope of the program that has rapidly grown in the process of responding to a major emergency, and the fact that the target area has been almost totally isolated from the outside world before the arrival of the NGOs, its effects seem to be predetermined. The introduction of cash, the development of trade and markets, and the formation of a town are all directly linked to the presence of NGOs; as are the consequent changes on people's lifestyle. By far the majority of these changes are seen as very positive by the beneficiaries as they are in line with 'development and progress', hence they are welcome. A positive impact on the health status of the population is attributed to the program, and explained by the ability of those who practice western medicine to recognise and consequently treat illness, which is experienced as a significant change to the traditional view that illnesses are caused by spiritual forces, witchcraft or curse and are categorised according to those. A gradual change in treatment seeking is being observed, away from traditional health care to an increasing trust in and utilisation of western medicine. However the findings of this study also point at one adverse effect of the program in the sense of a secondary change in treatment seeking away from the hospital to the newly emerged market. […] [Author p. 5]