Psychosis in childhood and adolescence is rare. Psychotic manifestations in childhood are associated with diagnostic diversities. The diagnostic group pervasive developmental disorder, not otherwise specified (PDD-NOS) are often used in childhood and may be a precursor of schizophrenia or affective psychosis. In this short review, expressions of psychosis in childhood and adolescence are listed and discussed. The authors speak in favour of a closer collaboration between child- and adolescent psychiatry and adult psychiatry clinically as well as in research contexts to expand the knowledge about the genesis and aetiology of psychoses.