Treatment of patients with suicidal behaviour is one of the most challenging tasks for health care professionals. Due to the high mortality, morbidity and costs related to suicide, the development of treatment and preventive strategies for suicidal behaviour have been a focus of psychiatric research. For lithium, one of the oldest pharmacological agents used in psychiatry, anti-suicidal effects have been found since the early 90s in many international studies. Despite this unambiguous evidence and corresponding recommendations in national and international guidelines for the acute and maintenance therapy of affective disorders, the use of lithium is still underrepresented. The following article provides a review of studies investigating the anti-suicidal effects of lithium in affective disorders. Clinical implications for the treatment of affective disorders are discussed.