Mortality estimates can be used for research, to inform or influence policy, for reconciliation processes, to plan health delivery and relief operations and for legal purposes. Many different methods have been applied and each has strengths and weaknesses. Recent years have seen an international effort in various disciplines like humanitarian actors, demographers and forensic anthropologists to cooperate, and efforts are being made to make data collection more systematic and valid. However, there are political, methodological and security-related challenges that must be overcome.