It is important to think strategically in the planning of health care provision for all populations and this is particularly true in rapidly modernizing countries which often have particular needs and limited resources to meet them. This paper discusses the general concept of epidemiological transition and its manifestations in three case studies of Hong Kong, Thailand and Mauritius. The general concept may be useful in anticipating health change particularly in countries in the middle income group as their economic and health status are frequently changing very rapidly. The consequences of epidemiological transition are considered, and the importance of developing awareness of needs of ageing populations for social care as well as medical care. The local context of the transition appears to be crucial to its ensuing implications. The paper concludes with a discussion of the potential and limitations of the concept of epidemiological transition for health planning. It may have utility in strategic thinking, sectoral resource allocation, the development of medical and paramedical education and training, and in determining future needs for essential drugs and equipment.