Objectives: To review the profile of children and adolescents presenting with psychosis at a specialist mental health facility, and to compare childhood with adolescent onset psychosis.Method: Hospital records of all children and adolescents over a 12-year period (1999–2010) were perused to identify those falling under the categories of psychotic disorders. Clinical, socio-demographic, obstetric, and developmental information was extracted.Results: Mean age of the children ((n = 409)) was 15.9 years, with 8.1% aged 12 years or less. The most frequent diagnoses were schizophrenia (40.8%), brief psychotic disorder (25.9%), mood disorder with psychosis (15.2%), and organic psychosis (7.8%). Family history of mental illness was reported among 22.5%. Subjects with childhood onset were significantly less likely than those with adolescent onset to have a family history of mental illness (p = 0.016), more likely to report maternal illness during pregnancy (p = 0.005) and illness during infancy (p = 0.010), and more likely to have a diagnosis of psychotic disorder due to another general medical condition (p < 0.001).Conclusion: The study suggests that antenatal/obstetric factors and illness during infancy may be particularly relevant in psychosis of childhood onset. Family history of mental illness may however be of greater relevance in adolescent onset psychosis