Suicidal behaviour includes suicidal ideation, parasuicide or attempted suicide, and completed suicide. Assessment and recording of suicidal ideation and parasuicide is most difficult, and the first internationally comparable data on parasuicide are expected from an ongoing WHO-coordinated study in 15 European centres. On the other hand, about 50% of WHO's 186 Member States report suicide as part of their mortality statistics. Although there is no uniformity in definitions of suicidal acts nor in recording procedures, certain patterns of suicidal behaviour emerge across countries. The incidence of parasuicide is 10 to 20 times higher than that of completed suicide; the male/female ratios for suicide and attempted suicide are reciprocal: 3 times more women then men commit parasuicide, while in most countries about 3 times more men than women commit suicide. From a public health point of view, suicide in adolescents and young adults is particularly important: suicide in adolescence and young adulthood ranks among the 5 leading causes of death in many countries. There have been clear and dramatic increases in suicide rates in most WHO Member States which report mortality statistics to the Organization, especially among young men. Suicide in old age, particularly among men, is about 2 to 3 times more frequent than in younger age groups. Although it is not surprising that mortality increases with age, death by suicide is considered in most cultures and by most people as particularly deplorable and unnecessary. The epidemiological analysis of suicidal behaviour globally does not identify clear-cut risk factors amenable to preventive programmes. It does, however, pinpoint countries with "unusual" suicide patterns which, it is hoped, will initiate country-specific research into causes of such behaviour. Particularly promising, from the perspective of suicide prevention, seems to be research into the methods of suicide, and the impact of publicity of suicidal acts, as it has been shown repeatedly that restricting access to the prevailing method of suicide in a country will decrease suicide rates, while wide publicity about suicidal acts will increase them.