This study investigates the relation of ego development, age, gender, & diagnosis to suicidality among 219 adolescent psychiatric inpatients using the Diagnostic Interview Schedule for Children. Adolescents were classified as suicide attempters or as nonsuicidal & were categorized into 3 diagnostic groups. A relation between suicide attempts & developmental complexity was demonstrated. Attempters were more likely to be diagnosed with affective or mixed conduct-affective disorders & to be girls.