The study examined whether having a family history of suicidal behavior is associated with an earlier age of first attempting suicide. Interviews were conducted with 545 patients who had attempted suicide about their family history of suicidal behavior and about their age of first suicide attempt. The results showed that attempters with a family history of suicidal behavior, particularly attempters with two or more such family members, had first attempted suicide at an earlier age than attempters who did not have a family history of suicidal behavior. These results suggest that a family history of suicide, which is known to increase the risk of suicidal behavior, may also be associated with an earlier age of first attempting suicide.