The incidence rate of hip fracture in Hong Kong in 1989 was calculated from hospital admission data and the census population. The incidence rate has increased 3-fold since 1966 to reach 9 per 1000 in men and 13 per 1000 in women 80 years and over. The age-adjusted rate was comparable to that in Singapore but higher than that in Japan. A case-control study was conducted on 280 women and 120 men with hip fracture and 800 controls. The relative risk for hip fracture increased with a low calcium intake, being 2.9 (95% confidence interval 1.9 to 4.6) in the lowest quartile. The relative risk for hip fracture was also significantly increased in subjects who did not perform load-bearing activity every day. Osteoporosis may be prevented by an adequate calcium intake and load-bearing activity in urbanized Asian populations.