Forty-three patients (two males and 41 females) were submitted to bilateral adrenalectomy for disseminated mammary carcinoma. Several factors were considered for their prognostic value in predicting the response to endocrine ablation. The age of the patients, the treatment of the primary lesion, the free interval, the location of metastases and the involvement of regional lymph nodes did not affect the response to adrenalectomy. Response to therapeutic castration was directly correlated to the response to adrenalectomy (P less than 0.01); this is a valuable predicting factor that should be taken into consideration before proceeding to bilateral adrenalectomy. A statistically significant variation in survival between the responders and nonresponders was found (P less than 0.05). Finally, the high response rate to the operation (53.4%) can be attributed to the complete removal of the adrenal tissue during the operation.