Takotsubo cardiomyopathy (TCMP) is known as stress cardiomyopathy, and long-term prognosis is generally excellent if recovering from an acute stage. Both thyroid storm and diabetic ketoacidosis (DKA) are reported to be rare causes of TCMP. However, there are no studies discussing TCMP as induced by a combination of thyroid storm and DKA, and the prognosis is unknown. Herein we report an 81-year-old female with type-2 diabetes mellitus initially presenting with palpitation, chest tightness, and gastrointestinal symptoms. She was further diagnosed as TCMP after echocardiogram and coronary angiography, and DKA was confirmed later. However, the patient’s general condition didn’t improve under proper treatment. Thereafter, thyroid storm was discovered fortuitously. Despite appropriate treatment, the patient finally expired due to acute respiratory distress syndrome progression. This rare case reminds us that despite TCMP being a transient cardiomyopathy with good prognosis, physicians should survey the possible underlying disease cautiously to avoid catastrophic clinical outcome.