The aims of this study were to estimate the present and future incidence of hip fracture world-wide. From a survey of available data on current incidence, population trends and the secular changes in hip fracture risk, the numbers of hip fractures expected in 2025 and 2050 were computed. The total number of hip fractures in men and women in 1990 was estimated to be 338000 and 917000 respectively, a total of 1.26 million. Assuming no change in the age- and sex-specific incidence, the number of hip fractures is estimated to approximately double to 2.6 million by the year 2025, and 4.5 million by the year 2050. The percentage increase will be greater in men (310%) than in women (240%). With modest assumptions concerning secular trends, the number of hip fractures could range between 7.3 and 21.3 million by 2050. The major demographic changes will occur in Asia. In 1990, 26% of all hip fractures occurred in Asia, whereas this figure could rise to 37% in 2025 and to 45% in 2050. We conclude that the socioeconomic impact of hip fractures will increase markedly throughout the world, particularly in Asia, and that there is an urgent need to develop preventive strategies, particularly in the developing countries.