The present study examines the unique and shared risk factors for suicidal behaviour, self-injury, and externally focussed aggressive behaviour among German youths and adolescents of both sexes. Also explored is the issue of multiple maladaptive behaviours and whether or not these are interrelated. The period of the sample comprised 2002-2003 admissions (N = 3694) to a clinic for child and adolescent psychiatry and psychosomatics. Measures were taken from medical-psychological documentation ("Ba-Do") and self-report questionnaire and included items relating to self-injurious behaviour, suicidal intent and socially disruptive and threatening behaviour (FAPS). Self and expert ratings of suicidal and self-injurious behaviour were significantly statistically correlated. Overt aggression was unrelated to suicidal behaviour. Suicidal and self-injurious behaviour were more common among female than male adolescents. Age, disharmony within the family and excessive parental demands were major global determinants of suicidal behaviour for both genders, but unrelated to self-injurious or socially disruptive behaviour, the latter being more associated with parental under-involvement and feelings of hostile rejection. Intelligence and age were significant predictors of overt aggression among females; intellectual functioning, number of siblings and disability among family members emerged as major determinants of suicidal behaviour among males. Findings are discussed in terms of practice interventions.