Objective: The primary objective of this review is to examine the demographic and nutrition transition in India in relation to its contribution to the emerging epidemic of chronic non-communicable diseases in this country. Setting: India, the country as a whole and its different states with a population exceeding 1 billion in 2001. Subjects: The review examines demographic changes in the population with consequent effects on the population pyramid, the rapidity and rates of urbanisation with striking variations in chronic disease patterns and the trends in obesity between rural and urban communities, attempting to relate their prevalence with the diet and lifestyle changes accompanying them. Design: The review is based largely on representative large-scale surveys in the country and other reliable documented data on population characteristics. It also includes a review of the published literature. Results: The results indicate that the demographic changes, rates of urbanisation and changes in dietary patterns are contributing to the changing trends in chronic disease in India. Conclusions: There is clear evidence of a demographic, epidemiological and nutrition transition in India that is fuelling the epidemic of chronic diseases and obesity, particularly in the urban areas.