To evaluate the effect of treatment with β-conglycinin, a major soyabean protein, on blood lipids in menopausal women, we recruited 100 hyperlipidaemic women aged 40–60 years old. Participants were randomly allocated to three groups: placebo group (n 34, four casein tablets/d); low dose group (n 33, four tablets containing 2·3 g β-conglycinin/d); high-dose group (n 33, eight tablets containing 4·6 g β-conglycinin/d). The mean serum TAG concentration was significantly reduced after 6 and 12 weeks of β-conglycinin intervention by 0·44 (sd 0·20) and 0·78 (sd 1·03) mmol/l in the low-dose group, and by 0·46 (sd 0·17) and 1·25 (sd 1·06) mmol/l in the high-dose group, respectively. One-way ANOVA revealed that serum TAG concentrations in the low-dose and high-dose groups were significantly lowered compared with the placebo group at weeks 6 and 12 (P< 0·05). The low dose and high dose consumptions of β-conglycinin significantly decreased the LDL-cholesterol concentration by 0·46 (sd 0·72) and 0·52 (sd 0·97) mmol/l at week 12, respectively (P< 0·05). Compared with the changes from baseline in the placebo group, apoB and NEFA were significantly lowered in both the low-dose and high-dose β-conglycinin groups (P< 0·05). In conclusion, the results suggest that β-conglycinin intake significantly decreases serum TAG and LDL-cholesterol levels.