Abstract Disclosure: S.M. ALShehri: None. M.S. Bafadel: None. N.J. Aljohani: None. Thyrotoxic crisis (thyroid storm) is a severe form of hyperthyroidism. It has a wide range of symptoms, including cardiovascular manifestations that can be life-threatening and require prompt management. Cardiac manifestations of thyroid storm include hypertension, tachycardia, congestive heart failure, cardiac ischemia, and atrial fibrillation. Standard therapeutic approaches of thyroid storm are based on the use of thionamides, corticosteroids, and nonselective beta-blockers to inhibit thyroid hormone synthesis and release while also blocking thyroxin's peripheral effects. This approach is an effective measure in the management of these manifestations. However, when a patient fails to respond to conventional therapy or there is end organ damage and surgery is not feasible, therapeutic plasma exchange (TPE) is a life-saving measure. Here, we report a case of a 32-year-old female who is known to have hyperthyroidism, but she was not compliant with her medication. She presented with symptoms of hyperthyroidism and was found to have thyroid storm with refractory atrial fibrillation. Despite the effort to control her symptoms, she developed cardiac arrest, after 15 minutes of cardiopulmonary resuscitation she revived. Amiodarone, beta blockers, and cardioversion have all failed to improve the patient's status, and her condition has deteriorated. So, we decided to use TPE, and she received three sessions in total. After the first session of TPE, her rhythm converted to sinus rhythm, and her heart rate was controlled to less than 100 beats per minute. She showed dramatic improvement clinically and biochemically. In conclusion, cardiac complications are potentially lethal complications of thyroid storm. Prompt restoration of a normal thyroid state can reverse these complications. When conventional therapy fails to ameliorate symptoms or organ deterioration is rapid and severe, TPE can be a safe and effective measure. Presentation: Thursday, June 15, 2023