Seventy-two women with advanced breast cancer were treated with aminoglutethimide and hydrocortisone (AG). All patients were previously treated with hormones and 59 patients had also received cytotoxic agents. A partial response to AG with a mean duration of 9 months (range: 4-26 months) was achieved in 24 patients (33%), 10 patients (14%) had stable disease, and 32 patients (44%) were progressing during AG therapy. Response to previous treatment seemed to be correlated to response to AG, as 47% of patients having responded to the first hormonal treatment also responded to AG, while only 16% of the progressors responded to AG. The number of previous treatments influenced neither the frequency nor duration of response to AG. The median survival after start of AG was 13 months, and 31% of the patients lived more than 2 years. Side-effects led to discontinuation of therapy in 9 patients (13%). Three patients developed reversible agranulocytosis.