Objective: Increase in severe psychopathology in adolescents who are resistant to common treatment creates a need to search new alternatives in pharmacological treatment. Background: To describe a sample 47 child and adolescent patients treated with clozapine between 1985 and 2010, indicating: age, gender, diagnoses, hospitalization, electroconvulsive therapy, dosing, adverse effects specially hematological ones. Methods: 47patients between the ages of 10 and 18 were treated with clozapine. Review of clinical charts, protocol investigation and Excel statistic analysis. Results: The sample consisted in: male: 40%, female: 60%, the youngest was 10 and the oldest 17years and 11 month old; the most frequent age was 15 years. The mean number of hospitalization was 1.5. Diagnosis Axis I,DSM IV: Affective disorders 64%, Schizophreniform disorder 23%. Electroconvulsive Therapy: 57%. Treatment indications: irreducible psychosis 23%, suicidability: 33%. Average dosing200 mg. Adverse effects: sedation: 76%, hypersalivation: 68%, increase in weight: 66%.Neutropenia: not severe (more than 2000/ mm³): 17%; severe 1:15%, severe II: 2%, severe III: 2%. Conclusions: Clozapine appears as an effective drug, with moderate but frequent adverse effects. Hematologic adverse effects where transient; only one in 47 patients presented a severe neutropenia and require cancellation of treatment, which was reinstalled after three month without mayor side effects. There is a need for control studies with larger population and a longer period of time.