BACKGROUND: The validity of a sub-classification of affective psychosis according to the mood congruence of psychotic features has been questioned in the literature. While some authors have found a correlation between such symptoms and outcome, their predictive value was rather limited in these studies. METHOD: Prospective study of 108 subjects presenting with a first DSM-III-R manic episode with psychotic features to determine the frequency of different types of psychotic symptoms and to measure the predictive utility of mood incongruent psychotic symptoms (MIPS) and first-rank Schneiderian symptoms (FRSS) during the first episode for a 12-month outcome. Outcome was measured by the level of positive, negative, depressive symptoms, and psychosocial functioning. Duration of affective and psychotic symptoms was also assessed. RESULTS: Patients presented with a wide variety of psychotic symptoms. The presence of MIPS at baseline was significantly correlated with a longer persistence of psychotic symptoms, but not with poorer outcome at 12 months. By contrast, the presence of FRSS at baseline was significantly associated with earlier onset of psychosis as well as increased severity of negative symptoms and poorer psychosocial functioning after 12 months. CONCLUSION: The presence of FRSS during a first manic episode with psychotic features identifies a sub-group of patients with more severe presentation and poorer short-term outcome. These results question the prognostic utility of MIPS. Limitations: Despite the relatively large number of subjects compared with other studies, the statistical power to detect all but large effect sizes is limited by the sample size.