The author briefly outlines important classifications of schizophrenia from this century, with emphasis on the current interest in the distinction between psychotic symptoms categorized as positive (for instance delusions, hallucinatory behaviour and grandiosity) or negative (for instance flat affect, and emotional or social withdrawal). Knowledge about the practical meaning and clinical consequences of this positive-negative distinction can be useful for staff at outpatient clinics and for general practitioners involved in community care and treatment of schizophrenia. The Positive And Negative Syndrome Scale (PANSS) for schizophrenia is briefly presented and recommended.