There is evidence of an increased incidence of schizophrenia in Afro-Caribbean immigrants to the UK and in Surinamese- and Dutch Antillean immigrants to The Netherlands. We tested the hypothesis that second-trimester exposure to the 1957 A2 influenza pandemic, which swept through the Caribbean in the same period as it affected Western Europe, contributes to this phenomenon. The dates of birth of immigrants, discharged from a Dutch psychiatric institute with a diagnosis of schizophrenia, were examined for any effect of the pandemic. Individuals who were in their second-trimester of fetal life at the peak of the pandemic were at no greater risk of developing schizophrenia than controls.