This report presents a case of cerebral venous thrombosis and venous infarction in a diabetic patient, the third in the world literature (the second in a child). An 8-year-old male was admitted to the hospital due to abdominal pain, vomiting, polydypsia, and polyuria, lasting for 4 days. Laboratory studies revealed marked hyperglycemia and ketoacidosis. Two hours after admission the child lost consciousness. Emergency computed tomography performed 3 hours after admission (4 days after the onset of symptoms) revealed hyperdensity in the vein of Galen and superior sagittal sinus, consistent with thrombosis, accompanied by bilateral venous infarction. Follow-up computed tomography performed 6 days after admission (10 days after the onset of symptoms) documented evolution of thrombosis. Magnetic resonance imaging and magnetic resonance venography performed 22 days after admission (26 days after the onset of symptoms) confirmed venous infarction and thrombosis. This report discusses possible mechanisms of cerebral venous thrombosis in diabetic hyperglycemia and stresses the importance of imaging studies despite the extreme rarity of such cases.