Eighteen patients with advanced metastatic carcinoma of the breast who had been previously treated with other hormone therapy were treated with stanozolol in a pilot study to assess its efficacy and toxicity. In a heavily pretreated population of patients with advanced breast cancer, three patients (16.6%) had partial responses (PR) and five patients (27.7%) had stable disease (SD). Toxicity was far less than that expected with androgen therapy. Stanozolol should be investigated in large groups of patients to establish its role more fully in the management of metastatic breast carcinoma.