Cortisol, cortisone, 11-deoxycortisol and deoxycorticosterone were synthesized in large amounts in vitro by a metastatic tissue from an adrenocortical carcinoma. 2. Both 11 beta- and 21-hydroxylase were very active. 3. A secreting metastasis can be thus responsible for a biological relapse. 4. A metastasis originating from another secreting adrenocortical carcinoma was found to be non-secreting.