More than one-third of the population of Surinam has migrated to The Netherlands in the 1970s and 1980s. If selective migration explains the increased incidence in these migrants, one expects to find a very low incidence of the disorder in Surinam. We examined the medical records of the sole psychiatric hospital in Surinam and found that the mean annual rate of first admissions for schizophrenia or schizophreniform disorder (DSM-III-R criteria) in 1992 and 1993 was 1.61 per 10,000 (95% Confidence interval: 1.24-1.98 per 10,000), a normal figure. These findings constitute a challenge to the hypothesis that selection explains the increased incidence in the migrants. The possibility of an increased incidence of the disorder in Surinam (which might also explain the increased incidence among migrants) has not been ruled out by the results of this study.