Over 800 000 people are estimated to die worldwide by suicide. Based on psychological autopsy studies, nine out of ten subjects who die by suicide have likely suffered from a diagnosable mental disorder preceding death. Because primary health care in most countries provides services for the majority of patients with depressive or substance use disorders, this setting should be the first point of call for suicide prevention. However, despite this central importance, research on incidence and prevalence of suicide deaths, attempts, ideation, or risk factors for suicidal behaviour in primary care settings is quite limited. Information on risk factors is mostly extrapolated from psychiatric or general population epidemiological studies. For purposes of prevention, improving quality and continuity of care of depression and substance use disorders, as well as integrating brief psychosocial interventions into primary care to target suicidal behaviour, are factors of central importance.