Introduction: Thyroid storm is an extremely rare & severe form of hyperthyroidism, and when left untreated can lead to multiorgan failure and death. In this case, we present a 52-year-old female whose hyperthyroidism-like symptoms were thought to be due to acute cholecystitis, with post-operative course complicated by delirium & hemodynamic instability likely due to thyroid storm. Description: Patient is a 52-year-old female with a history of HIV, nephrolithiasis, hypertension, and migraine headaches who presents with right upper quadrant abdominal pain, nausea and vomiting for 2 weeks. She endorses poor appetite for 4 weeks with 30-pound weight loss in that period. In the ED, she was hypertensive and tachycardic. Labs are significant for hypokalemia and leukocytosis of 12.9. CT abdomen/pelvis demonstrated gallbladder wall thickening, trace pericholecystic fluid, right hydronephrosis, and acute cholecystitis. The patient underwent laparoscopic cholecystectomy with postoperative course complicated by acute delirium. She continued to deteriorate with BP 177/101, HR 181, and RR 31. She was given neuroleptics without improvement and transferred to the ICU for further management. Thyroid studies revealed hyperthyroidism; thyroid ultrasound revealed multiple isoechoic circumscribed thyroid nodules consistent with thyroid goiter. Burch criteria for thyroid storm was 70, highly suggestive of the condition. The patient was treated with esmolol and dexmedetomidine drips, propranolol for tachycardia, PTU to block conversion of T4 to T3, thionamide & iodine solution to block synthesis & secretion of T4, and hydrocortisone to reduce inflammation & block synthesis of T4 to T3. Discussion: The main challenge in this case is recognizing the overlap of symptoms of acute cholecystitis with underlying and undiagnosed hyperthyroidism. Thyroid storm usually presents as mimic, with this patient experiencing predominantly neuro-type presentations with delirium. The presence of new-onset delirium with hemodynamic instability post-operatively should raise a high index of suspicion for thyroid storm and must be treated without delay. Maintaining a broad differential prior to surgical intervention, a known trigger, could propel the clinician into considering underlying thyroid pathologies and prevent thyroid storm altogether.