OBJECTIVE: This research investigates personality variables--aggression and disorders of conduct, depression, and separation anxiety--mediating suicidal behavior in psychiatrically hospitalized urban minority adolescents. METHOD: Four matched groups of 26 subjects (N = 104) participated: suicidal adolescents with, and suicidal adolescents without, a conduct disorder diagnosis, nonsuicidal adolescents with a conduct disorder diagnosis, and a nonpsychiatric control group. Subjects were assessed with three dimensions from the Epigenetic Assessment Rating System (EARS), the Children's Depression Inventory (CDI), and the Separation Anxiety Test (SAT). RESULTS: A conduct disorder diagnosis was related to lower modal EARS scores. The EARS and the CDI each identified a different subset of suicidal adolescents. Adolescents with lower modal EARS scores exhibited greater reactivity to separation experiences on the SAT. CONCLUSION: Relying on depressive symptomatology to identify suicidality overlooks a majority of at-risk adolescents. Structural personality variables as measured by the EARS identify and distinguish subsets of suicidal adolescents.