Suicide is a complex and multicausal human behavior and also a great challenge for psychiatry. We review the evidence available concerning pharmacological prevention of suicide in bipolar disorder patients. Several clinical trials provide evidence that effective acute and long-term treatment of bipolar depression provides a strong protection against suicide, suicide attempts, and probably against other complications of this disorder. Current major mood disorder is the most important risk factor of suicide, and bipolar II patients carry the highest risk. In bipolar patients suicidal behavior is most likely to occur during pure or mixed depressive episodes. Since bipolar disorder is a highly recurrent illness, adequate long-term pharmacotherapy is needed to prevent suicidal behavior.