There is a vast amount of information on the concentration of different androgens in human breast cancer in pre- and post-menopausal women. Many years ago it was suggested that some androgens, in particular dehydroepiandrosterone (DHA), could be one of the parameters to establish whether these androgens can predict breast cancer. However, the enormous data available on the plasma and tissue concentrations, particularly DHA and DHA sulfate (DHA-S) allow confirmation that the quantitative values of these androgens are not significantly different in normal women from those with breast cancer. Another important aspect of androgens in breast cancer is their function as precursors of estrogens, hormones which play an important role in breast cancerization. However, it is not clear at present what the quantitative contribution of androgens "via aromatase" is to the formation of estrogens, because more recently it was found that estradiol in breast cancer tissues originates mainly "via sulfatase" using estrone sulfate as precursor. A point of further interest is that a series of authors have demonstrated that the administration of DHA to experimental animals with breast cancer significantly decreased the evolution of the disease. This part of the data is also contradictory because other experimental information has shown that administration of DHA can increase the incidence of granulosa cell tumors. Finally, it has been suggested that androgens, in their capacity as anti-estrogens, can be used to substitute anti-estrogens in cases where treatment with classical anti-estrogens has no response. In conclusion, more information concerning the plasma and tissular concentrations of androgens, their contribution as estrogen precursors and their biological response(s), is needed in order to have a clearer idea of the role of these steroids in breast cancer.