We present the results of a review of the literature concerning gender differences in age at the onset of schizophrenia. In view of the very consistent finding that the first admission to hospital for schizophrenia occurs on average earlier in men than in women we examined the question whether this is due to the fact that the psychosis manifests itself earlier in men or that the period between first manifestation and admission to hospital is shorter than in women. By means of a metaanalytic approach we then looked for evidence for the existence of local or temporal variations in the degree of gender difference. Lastly, we dealt with the question whether gender differences in age of onset can be observed in other functional psychoses.