There is renewed interest in the revival of health co-operative as a "third option" for meeting health care needs of populations in developing countries in the context of health sector reforms. This article reviews some international experiences with health co-operatives. We briefly assess the history of health co-operatives in industrialized countries where they originated and review past experience from China and the states of Kerala and Gujarat in India to explore the viability of health co-operatives for the provision of health care. In industrialized countries, co-operatives came into existence as autonomous entities with voluntary participation, aiming to contribute to the welfare of their members. In recent years, however, co-operatives are being envisaged as a mechanism to overcome economic barriers in access to health care, despite lack of evidence of their cost-effectiveness and sustainability. In China, health co-operatives achieved universal coverage of basic health services but became dysfunctional when state support was withdrawn. In Gujarat/India, co-operatives have been useful to provide primary health care services and not as a mechanism to run hospitals and provide medical care for the general population. In Kerala/India, health co-operatives could not successfully compete with expanding state health services and private services unless they were managed like private enterprises. In terms of managerial effectiveness and sustainability co-operatives can not be "prescribed" to compensate for the deteriorating access to health services following market-oriented health sector reforms in developing countries.