The incidence of schizophrenia and other psychotic disorders is very high among several ethnic minority groups in the Netherlands, and is most increased for Moroccans. This study compared symptoms at first treatment contact for a psychotic disorder between 117 native Dutch and 165 ethnic minority patients from Morocco, Surinam, Turkey, other non-Western countries and Western countries, using data from an incidence study for psychotic disorders over 4 years in The Hague, the Netherlands (1997-1999 and 2000-2002). Patients were examined using the Comprehensive Assessment of Symptoms and History (CASH), which includes the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS), and a section on DSM-IV mood disorders. Differences between native Dutch and ethnic minorities in SAPS, SANS, total psychopathology (SAPS plus SANS), proportions of patients meeting the criteria for a current manic or depressive episode, and differences in individual symptoms were investigated using regression analyses. Moroccans had higher total psychopathology and total SANS scores than native Dutch, and particularly presented more often with persecutory delusions. Moroccans and Turks more often met the criteria for a depressive episode. The other ethnic groups did not differ from native Dutch in levels of psychopathology. These results suggest that Moroccans not only have the highest risk of schizophrenia of all ethnic groups in The Hague, but that they are also more severely ill at first treatment contact. Experiences of social adversity, which have been associated with persecutory delusions, and cultural factors may contribute to the observed differences in severity and content of psychopathology between Moroccans and native Dutch.