Most emergency care facilities in tropical areas are inefficient, underequipped, and quickly overwhelmed by the ever-growing attendance. As a result, mortality is higher than in developed countries. To speak in terms of natural selection would be tantamount to a fatalistic admission of powerlessness to deal with the situation. In Africa, the gross imbalance between supply and demand makes it necessary to make hard choices in order to make the most effective use of available staff and equipment. The objective of medical triage is to allocate scarce facilities to those patients with the greatest chance of survival. However it is difficult to define precise rules for making such choices since they are strongly dependent on available resources, type of pathology, and level of medical skill. Prognostic indicators are ill-suited to emergency situation since they require not only clinical data but also and above all, in most cases, laboratory data which is not always available or justifiable. Experience is probably the best guarantee for reliable triage, which is philosophically difficult to accept but often unavoidable in everyday practice.