Cross-cultural investigations of schizophrenia and other psychotic disorders have a long tradition of attempting to assess both the universal and cultural variability of these phenomena. Research in this area received a major boost from the innovative multinational and multicentric studies conducted by the World Health Organization. Results showed that there were certain similarities, such as in incidence/prevalence, as well as differences, such as in clinical manifestations, in presentation across cultures. The most striking difference, however, was the benign course and outcome of schizophrenia in developing countries compared with developed ones. Reasons for this difference are not entirely clear, but it appears that culturally determined processes are at least partly responsible, thereby meriting further examination.