Information on the association of impulsivity and measures of aggression with suicidal ideation in adolescents and young adults is limited. Data were gathered from a community sample of 625 adolescent and young adult males. Analyses were based on multivariate generalized estimating equations. Impulsivity and irritability were associated strongly with suicidal ideation after accounting for alcohol dependence and other aggression-related constructs including psychopathy. Given that irritable, impulsive adolescent males appear to contemplate suicidal behavior, their heightened suicide risk may be anticipated and mitigated.