Based on information from a case register, patient age and diagnosis at first admission are analysed in a Croatian cohort of schizophrenics first admitted in 1972 and followed up through the register for 12 years. Diagnosis was analysed on the same basis and over the same period. Although the male and female differences in incidence rates for schizophrenia were not large, hospital incidence rates in younger age groups were higher in males. Males were also more commonly diagnosed as schizophrenic at first admission, females more frequently receiving diagnoses of affective psychosis and other organic psychosis, except for alcohol-induced psychosis.