This paper reviews international data on incidence rates of hip fracture in persons 50 years of age and older, based on a bibliographic search of articles published since 1960. Incidence rates are higher in white populations than in black, Asian, and Hispanic populations. In both sexes and in all ethnic groups and geographic areas, incidence rates increase markedly with age. The steep increase with age, however, occurs later in black, Asiatic and Hispanic populations than in whites. The ratio of female to male incidence rates is higher than 1.0 in whites, while in blacks and Asians it has often been the reverse, with higher rates among men. In recent years in Hong Kong incidence rates in females have increased more rapidly than incidence rates in males, so that now the incidence rates in females are higher than those in males. In addition to the study in Hong Kong, most studies in Northern Europe and North America show an increase in age-adjusted hip fracture incidence rates over time over the past few decades. Methodological differences among the various studies (including differences in the definition of hip fracture, in case ascertainment, and in the selection and sample size of the study population) necessitate cautious interpretation of the findings of this report.