High maternal mortality was a feature of the Western world from the mid-19th century, when reliable record keeping commenced, to the mid-1930s. During this time, maternal mortality rates tended to remain on a high plateau, although there was wide disparity between countries in the height of the plateau. From Ϸ1937, maternal mortality rates began to decline everywhere, and within 20 y, the intercountry differences had almost disappeared. The decline in maternal mortality rates was so dramatic that current rates for developed countries are between onefortieth and one-fiftieth of the rates that prevailed 60 y ago. In this paper, the reasons for the high mortality before 1937 and its decline since that date are discussed. It is suggested that the main determinant of maternal mortality was the overall standard of maternal care provided by birth attendants. Poverty and associated malnutrition played little part in determining the rate of maternal mortality. This view is supported by much evidence, including the fact that, unlike for infant mortality rates, maternal mortality rates tended to be higher in the upper than in the lower social classes. The potential relevance of these findings to developing countries is discussed.Am J Clin Nutr 2000;72(suppl):241S-6S.