Suicidal behavior is a major health issue and is one of the most difficult phenomena to explain from an evolutionary point of view. Because strong ecological forces maximize self-preserving behaviors and reproduction, it seems paradoxical to find a genetic vulnerability to suicidal behavior. The main objective of the present chapter is to stress the relevance of an evolutionary framework of suicidal behaviour which is based on epidemiological, ethological, and life history data. This framework may provide a basis to generate a novel proximal hypothesis to test. Two prototypes of suicidal behavior are particularly congruent with regard to the theory of evolution: first, a young woman who uses suicide attempts to communicate a problem –usually, a break-up- to the rest of the group; second, an old man bearing either a somatic or a mental disorder, who is socially impaired and thinks that he is a burden for the group (altruistic suicide).