A 65-yr-old white man was hospitalized for an acute myocardial infarction, and heparin therapy was begun. Except for a mild pneumonitis without overt evidence of septicemia, he improved until the eighth hospital day, when acute abdominal symptoms developed, followed by coma and death. Autopsy disclosed a recent myocardial infarction and massive bilateral adrenal hemorrhage. Recent evidence indicates that excessive corticotropin ( ACTH ) stimulation, by either corticotropin administration or severe stress, may have a lethal effect upon the adrenal cortex; thus, the seriously ill patient may have an increased susceptibility to adrenal damage. The use of anticoagulants in such a patient should be cautious, since it may increase the hazard of adrenal hemorrhage.