Using as indices of risk the age at menarche, age at first child, family history of breast cancer and the amount of urinary aetiocholanolone excreted, 386 normal women aged 30-69 yr were divided into 4 groups with a mean calculated risk of breast cancer of 0.016, 0.023, 0.051 and 0.111. Plasma levels of dehydroepiandrosterone and its sulphate, androstenedione and androst-5-en-3β, 17β-diol have now been determined on blood specimens from the same women, taken approximately 5 yr after urine collection. The levels of plasma androst-5-en-3β, 17β-diol, dehydroepiandrosterone and its sulphate correlated with the excretion of urinary aetiocholanolone and were at the lower end of the normal range in the highest risk group. The significant correlation between plasma androgen levels and the amount of urinary aetiocholanolone measured 5 yr previously indicates that abnormalities in androgen production are not transient. © 1979.