A middle aged woman, having a history of diastolic hypertension and sinus bradycardia since one year ago, was referred to our center with a sudden occipital headache after shouting. To evaluate the cause of headache the brain MRI was performed reporting a slight cerebellar tonsillar herniation of about one centimeter below the foramen magnum. After the patient was diagnosed to have type I Chiari malformation, a surgery procedure was done and the symptoms were recovered after that.Type I Chiari malformation is a disease mostly caused by congenital displacement of cerebellar tonsils through the foramen magnum. The most common symptom is headache, rarely reported with hypertension or sinus bradycardia.