Bipolar disorder is associated with increased mortality because of complications of commonly comorbid substance use and stress-sensitive medical disorders as well as accidents and very high rates of suicide. Long-term lithium treatment may be associated with reduced suicidal risk. We review and summarize findings that help to quantify relationships between the presence versus the absence of lithium maintenance and suicides or attempts in patients with bipolar or other major affective disorders. Results from 33 studies (1970-2000) yielded 13-fold lower rates of suicide and reported attempts during long-term lithium treatment than without it or after it was discontinued. Although greatly reduced, these rates remain above those estimated for the general population. Evidence for substantial, if incomplete, protection against suicide with lithium is supported by more compelling evidence than that for any other treatment provided for patients with mood disorders. Studies of commonly used, but incompletely evaluated, alternative treatments are required, and further protection against premature mortality can be anticipated with better protection against bipolar depression.