In Hong Kong physical activity and calcium intake of 400 Chinese men and women with hip fractures were compared with those of 800 controls. Daily walking outdoors, upstairs, uphill, or with a load protected against fracture. This was independent of cigarette smoking and alcohol consumption. Higher levels of reported activity in middle life were also protective. Average calcium intake was around one quarter that in Britain because of the low consumption of dairy products. Differences in calcium intake depended mainly on consumption of green vegetables and small fish. High intake protected against hip fracture. These findings point to the importance of maintaining daily physical activity and calcium intake in urbanised Chinese populations.