We describe the pattern of soy intake and its association with blood lipid concentrations in the Hong Kong Chinese population. Subjects were contacted by random telephone survey and invited to a hospital for a physical examination and blood tests. A total of 500 men and 510 women with an age range of 24-74 y completed the dietary intake study. The dietary assessment was based on a semiquantitative food frequency questionnaire that included 10 commonly consumed soy items. Many (88%) of the study population had consumed some soy products during the previous week. About 80% of the soy protein or isoflavones were obtained from different forms of tofu, and an additional 9% was obtained from soy milk. The mean weekly isoflavone intake was 102 +/- 107 mg in men and 77 +/- 90 mg in women. In men, soy intake and total plasma cholesterol were negatively correlated (r = -0.09, P: = 0.04), as were soy intake and LDL cholesterol (r = -0.11, P: = 0.02). The respective values in women <50 y old were r = -0.11, P: = 0.04 and r = -0.11, P: = 0.05. Soy protein remained significantly associated with these two lipid concentrations after adjustment for other social and dietary confounders. Higher soy intake seemed to be related to a better plasma lipid profile in men and in younger women, but more epidemiological studies and controlled clinical trials in this setting would help to confirm the optimal amount required for the prevention and treatment of hyperlipidemia.