No differences in steroid hormone receptor status were detected in premenopausal breast cancer patients of different races. In postmenopausal women, 65% of Whites were found to have tumors positive for cytoplasmic estrogen receptors (CER) compared with 58, 52, and 41% in women of mixed race, Blacks, and Asians, respectively. The proportions of tumors which contained a full complement of receptors (CER, nuclear estrogen receptors, and cytoplasmic progesterone receptors) were similar in Blacks, Whites, and Asians in each menopausal group. In postmenopausal patients, significantly fewer White women had tumors devoid of all receptors, while having a higher incidence of tumors with an abnormal or defective receptor distribution. Neither the stage of the disease nor the degree of nodal involvement appeared to affect receptor status in any population group, but very large tumors had fewer receptors. White patients with large neoplasms had a significantly higher incidence of CER than Blacks or Asians. Similar observations were made for White patients presenting with Stage III disease, whose tumors were greater of histological Grade I tumors were positive for CER, compared with Grade III neoplasms. Indications are that receptor status is inherent to the natural history of the disease and is not influenced by clinical features.