Objective: Both mood disorder and suicidal behavior are familial. In this study, the authors examine the factors associated with the familial transmission of these two related conditions to learn which are shared or unique risk factors for familial transmission. Method: The 285 offspring of 141 probands with mood disorder were studied. Proband and offspring characteristics associated with offspring mood disorder were examined by univariate statistics, logistic and Cox regression, and path analysis. Results: Parental history of sexual abuse was associated with an increased risk of offspring mood disorder. The relationship between parent sexual abuse and offspring mood disorder was mediated by offspring impulsive aggression, sexual abuse, and anxiety disorder. In offspring, higher levels of impulsive aggression were associated with earlier age at onset of mood disorder. Offspring suicide attempt was mainly related to offspring mood disorder, with additional contributions from offspring sexual abuse and impulsive aggression. Conclusions: The pathways associated with the familial transmission of mood disorder and of suicide attempt are similar but not identical. Prevention of early-onset mood disorder by targeting high--risk families may help to prevent the transmission of suicidal behavior. Because these data are cross-sectional, these results must be confirmed by prospective follow-up. J. Am. Acad. Child Adolesc. Psychiatry, 2004;43(10):1259-1266. Key Words: depression, suicidal behavior, family transmission.