Our prospective Zurich study (1978-2008) found that suicidal ideation had occurred in 40.5% and suicide attempts in 6.6% of the population by age 50. Important gender differences were found in both suicidality and its risk factors. Suicide attempts were earlier and more frequent among women than among men: 70 versus 44% reported their first suicide attempt before 20. For women, the relative risk of suicide attempts was 1.6, but the relative risk of suicidal ideation was about equal (1.1 for women). The main risk factors for suicidal ideation in women were low social support (OR 4.0) and frequent punishment in childhood (OR 3.7), and in men, a depressive (OR 6.5) and an anxious personality (OR 4.6). The main risk factors for suicide attempts in women were a broken home (OR 10.2) and sexual abuse/violence (OR 7.9) in childhood; in men, no multivariate analyses of suicide attempt were conducted because of insufficient statistical power.