Urbanization in developing countries involves changes in social support and life events which have been shown to affect mental health; mainly depression and anxiety, particularly among low income women. Although depressive and anxiety disorders have a high prevalence and account for a large proportion of visits to primary health services there is little international health research in this field. The determinants, extent and outcome of the association between urbanization and mental health requires multi-disciplinary research by social scientists, social psychiatrists and public health professionals. An appreciation of different conceptual models and associated methods is required before effective research can begin. Other issues such as the avoidance of environmental determinism; the separation of macro-social and micro-social variables; the weakness of urban/rural comparisons of mental health; the role of rural to urban migration; the debates about cross-cultural psychiatry; and the policy-relevance of research, all need consideration in the development of research into this rapidly emerging, but relatively neglected problem.