Giant negative T waves or massive T wave inversion are defined by the presence of negative T waves with an amplitude ≥1 mV in at least two consecutive electrocardiographic leads. A 66 year-old asymptomatic woman who underwent a routine medical examination was admitted in the CCU due to the presence of giant negative T waves in leads I, II, aVL, aVF and from V1 to V6, and a left anterior hemiblock. She had a history of type IV dyslipemia and mild hypertension. The ischemic etiology of T-wave inversion was ruled out. During follow-up, T waves progressively became less negative and 45 days later they normalized. The origin of Twave inversion could not be established.