Schizophrenia and other psychotic disorders are associated with increased risk of developing type 2 diabetes. However, previous studies are mainly based on clinical samples where the comorbidity may be stronger. We investigated in a general population survey the prevalence of type 2 diabetes in persons with psychotic disorders and in users of antipsychotic medication. The study was based on a nationally representative two-stage cluster sample of 8,028 persons aged 30 or over from Finland. Diagnostic assessment of psychotic disorders combined SCID-I interview and case note data. Prevalences of type 2 diabetes, adjusting for age and sex, were estimated by calculating predicted marginals. The prevalence estimate of type 2 diabetes was 22.0% among subjects with schizophrenia, 13.4% among subjects with other nonaffective psychosis and 6.1% in subjects without psychotic disorders. Only two subjects (3.4%) with affective psychosis had type 2 diabetes. Users of all types of antipsychotic medication had increased prevalence of type 2 diabetes. Our results suggest that type 2 diabetes is a major health concern among persons with schizophrenia and other nonaffective psychotic disorders and also in users of antipsychotic medication, but persons with affective psychosis in the general population may not have increased prevalence of type 2 diabetes.