Fifteen consecutive patients with metastatic carcinoma who demonstrated bilateral adrenal metastasis on abdominal computed tomography (CT) were evaluated by the cosyntropin challenge test. Primary sites of tumors included lung, ten; colon, two; gastric, one; ovarian, one; and unknown primary, one. Bilateral adrenal enlargement was defined as greater than 1 cm on CT scan. Adrenal insufficiency was defined as a failure to increase serum cortisol by at least 5 micrograms/100 ml to a minimum of 15 micrograms/100 ml at either 30 or 60 minutes postcosyntropin. No patient had previously been on corticosteroids. All patients were questioned and examined for symptoms/signs of adrenal insufficiency. Five patients (33%) were found to have adrenal insufficiency based on the cosyntropin test. Of the clinical parameters evaluated, all five patients had nausea, anorexia, and orthostatic hypotension. The clinical onset of adrenal insufficiency was insidious; no patient experienced acute adrenal crisis. We conclude that adrenal insufficiency is not a rare occurrence in patients with metastatic cancer and bilateral adrenal involvement on CT scan.