A 65-year-old man with diabetes mellitus was presented with left visual aura, followed by a versive seizure, each lasting approximately 3 minutes. Neurological examination showed an intermittent left homonymous hemianopsia. Brain magnetic resonance imaging (MRI) showed right occipital lobe lesion, with cytotoxic edema. Blood glucose was 593 mg/dL and serum osmolarity was 309 mOsm/kg. The seizures were controlled by normalization of blood sugar and short-term anticonvulsant, and the lesions were resolved in a follow-up MRI. We report a case of visual seizures associated with non-ketotic hyperglycemia.