The morbidity and mortality survey conducted by WHO in 2005 showed the health gains attained through the largest humanitarian operation in the world. During 2006, however, the security situation has become more and more unpredictable and volatile, impacting on the coverage and effectiveness of the humanitarian response, including its health component. The demand for health services assistance in Darfur has steadily increased since the beginning of the crisis. However, the total input of resources has dropped considerably because of diminished funding, deteriorating security and decreased access, as well as spiralling logistic costs. As a result, the health care services coverage has dropped below 60% from 75% in early 2006.