We report a case of a 61-year-old female patient who presented with palpitations. The baseline electrocardiogram showed incomplete right bundle branch block with saddle back pattern of the ST segment in one precordial lead, but without any significant ST elevation. She was treated with oral cibenzoline. The subsequent ECG showed a coved Brugada ECG (type I) pattern, which resolved following the discontinuation of cibenzoline. An ajmaline test reproduced the coved type Brugada ECG pattern. Our case is the first report of oral cibenzoline therapy unmasking the diagnostic coved Brugada ECG pattern in a patient with a baseline normal ECG. Cibenzoline, a class I sodium channel blocker antiarrhythmic drug, should probably be avoided in the treatment of patients with Brugada syndrome.