Suicide in the elderly raises the question of our relationship with aging and death. Suicide rate is relatively high in this group and is significantly related to depression widely under-diagnosed in the elderly. Suicidal behaviour in the elderly has clinical specificities including high intentionality and lethality, usually little personal history of suicidal behaviour and low levels of impulsivity-aggression. Suicidal vulnerability could rely on etiopathogenic mechanisms both common and different according to age; for example, a preponderance of early developmental factors and impulsivity-aggression in adolescents and young adults vs. pathological aging in older adults, but partly similar neurocognitive deficits leading individuals not to respond adequately to their environment (itself different with age). Direct comparisons between elderly and younger subjects would be required. The article concludes with a summary of the principles of recognition and management of suicide risk.