Normal adrenocortical activity is necessary for electrolyte regulation and the maintenance of cardiovascular function. Although chronic adrenal insufficiency generally presents with the gradual onset of a set of characteristic symptoms and signs, the more sudden loss of adrenal activity can present with acute, rapidly progressive cardiovascular dysfunction that can be fatal if not recognized and treated promptly. We herein describe a patient who had most of his adrenal tissue removed during resection of metastatic renal carcinoma, conventional clear cell type, with much of the remaining adrenal tissue undergoing necrosis during or shortly after surgery. Although the patient appeared to be stable and progressing adequately well, he died suddenly 2 days postoperatively. When the gross autopsy findings suggested the possibility of adrenal insufficiency, clinical laboratory assessment of adrenocortical activity was sought. Analysis of stored antemortem serum samples and of blood obtained at autopsy demonstrated a progressive decrease in cortisol levels which, in this stressed postsurgical patient, proved fatal. The use of both antemortem and postmortem blood in the demonstration of acute adrenal insufficiency at autopsy is discussed.