A 53-year-old male with a past medical history of hypertension and bipolar disorder gradually developed gait disturbance and cognitive dysfunction over half a year. His cranial MRI showed an area of hyperintensity in the right occipital lobe on T2 weighted images and the surface of the lesion was enhanced along the sulci. We diagnosed his condition as amyloid-β-related angiitis (ABRA) based on brain biopsy. Repeated, frequent seizures resistant to several antiepileptic drugs (AEDs) occurred after the operation. Steroid therapy was effective and the symptoms, including the intractable seizures and MRI abnormalities dramatically improved. In contrast to the common wild type ε3/ε3 ApoE genotype, a majority of ABRA patients have ε4/ε4. However, in this case the rare ε4/ε2 type was detected. The ε4 allele is considered to promote Aβ deposition on the vessel wall, and ε2 is speculated to trigger vessel ruptures or vascular inflammation. Although seizure is not a common complication of brain biopsy, it occurred repeatedly and responded poorly to AEDs in this case. Surgical stress in this patient with ε2 probably induced the uncontrolled seizures. ApoE genotype may be an effective and low-invasive marker in case of suspected ABRA and in predicting the risks of the complication from brain biopsy.