A 45-year-old male patient with an irregularly irregular rhythm and fast ventricular rate was posted for an emergency laparotomy for hollow viscus perforation. His history was not suggestive of any systemic disorders. An echocardiography revealed left ventricular dysfunction with an ejection fraction of 47% without any valvular or chamber abnormality. Thyromegaly noticed during placement of central venous catheter was suspected to be the etiology for his cardiovascular status and was successfully managed. Thyroid crisis in an undiagnosed case of hyperthyroidism poses a diagnostic and therapeutic challenge. Timely and aggressive management is essential to correct the homeostatic decompensation characteristic of thyroid storm.