Abstract Disclosure: A. Jamil: None. N. Mohammad: None. S. Narayana: None. Background: Adrenocortical carcinoma (ACC) is a rare endocrine malignancy of the adrenal glands with a poor prognosis that often presents with excess hormone secretion. Approximately, 45% of cases present with hypercortisolism.1 A key component of management is achieving control of hypercortisolism. Though there are multiple enteral therapies that can inhibit cortisol production, few treatment options are available for use in critically ill patients who are not surgical candidates and cannot take oral medications. Though primarily known as a short-acting intravenous anesthetic agent used for sedation, etomidate also inhibits 11-β-hydroxylase, a key enzyme involved in corticosteroid biosynthesis.2 Clinical Case: A 28-year-old woman with metastatic adrenocortical carcinoma with associated hypercortisolism was initially admitted for anemia and thrombocytopenia, with an initial cortisol on admission of 29.3 μg/dl (normal range: 2.3-19.4 ug/dl). Due to her large tumor burden with metastasis to the liver and invasion into the inferior vena cava, she was deemed a poor surgical candidate with a poor overall prognosis. Her hospital course was complicated by acute hypoxemic respiratory failure requiring intubation, and thus her enteral steroidogenesis inhibitors (mitotane, ketoconazole, and metyrapone) were discontinued as none were administrable via nasogastric tube. Consequently, her hypercortisolism worsened rapidly with a cortisol level of 351.3 μg/dl , prompting initiation of continuous low-dose etomidate infusion, which resulted in significant improvements in her cortisol levels. After eight days of etomidate treatment, her cortisol levels reached a goal value of 25.0 μg/dl. However, she then suffered an ischemic cerebrovascular event and multiorgan failure, and was subsequently transitioned to hospice care. Conclusion: Low-dose etomidate infusion is an effective therapeutic agent for hypercortisolism in patients with ACC that are unable to take oral medications.