OBJECTIVES This partly waitlist-controlled prospective field study aimed to evaluate the effectiveness of psychoanalytic psychotherapy for children and adolescents with severe externalising symptoms. Externalising symptoms are associated with diagnoses of conduct disorders, hyperkinetic disorders, and disorders of social functioning. METHODS Participants were 93 children and adolescents in psychoanalytic therapy with a diagnosed psychiatric disorder with externalising symptomatology (intervention group: n = 65; minimal supportive treatment/waitlist control group: n = 28). Data was collected from parents and patients (≥ 11 years) at beginning/end of treatment, 6- and 12-month follow-up. The effects of long-term psychoanalytical treatment were analysed using a longitudinal design. RESULTS At the end of therapy, externalising symptoms were significantly reduced rated by both parents and patients (parent-rated: d = .69, patient-rated: d = .63). This effect was stable at the 1-year follow-up (parent-rated: d = .77, patient-rated: d = .68). About 70% of the patients may be considered as recovered or improved by the end of therapy. CONCLUSIONS Psychoanalytic therapy may be successful in alleviating psychiatric disorders with externalising symptoms with effects stable at the 1-year follow-up.