Bipolar disorders are common but frequently under-referred, underdiagnosed, and undertreated illnesses with markedly elevated premature mortality. Up to 15% of patients with bipolar disorder (BD) die by suicide, and about half of them make at least one suicide attempt in their lifetime. The suicide rate of (untreated) BD patients is 20–25 times higher than the same rate in the general population. Suicidal behavior (completed suicide and suicide attempt) in BD patients occurs almost exclusively during the severe major (often mixed) depressive episode and less frequently in mania with mixed features but very rarely during euphoric mania, hypomania, or euthymia; this suggests that suicidal behavior in BD patients is a state- and severity-dependent phenomenon. However, since the majority of BD patients never commit suicide (and up to 50% of them never attempt it), risk factors other than BD itself also play a significant contributory role. This chapter summarizes the clinically most relevant suicide risk and protective factors in BD and also briefly explores the most effective suicide prevention strategies.