A case of superior sagittal sinus thrombosis was reported. A 23-year-old male was admitted to our clinic on August 16, 1978, because of generalized convulsive seizures. he had complained of severe headache and high fever for about 7 days before admission, and on admission he was in slightly drowsy state. At that time, bilateral choked discs and bilateral abducens pareses were found without any other neurological deficit. CT scan on his 1st hospital day revealed only slight compression of the ventricular system without any midline shift. On the 2nd hospital day, he developed sudden left hemiparesis, but his level of consciousness did not deteriorate as that of the previous day, demonstrating clear CSF by lumbar puncture. Right CAG on August 21 revealed delayed circulation, poor-filling of the cortical veins, and narrow superior sagittal sinus showing zigzag shaped margin. CT scan on August 22 showed multiple irregular high dense foci mainly in both parietal lobes and the shift to the left of the ventricular system. Besides, on enhanced CT scan, the so-called "empty triangle" sign was revealed with gyral enhancement. Although an increase of the shift of the ventricular system was demonstrated by the follow-up CT scans, he gradually improved and external decompression was necessitated no longer. He was discharged with slight weakness of the left upper limb after superior sagittal sinus showing good-filling on right CAG performed on September 27 and had been identified. As a result, it was confirmed that in case sinus thrombosis is doubted, follow-up study by CT scan would be significant for the choice of treatments as well as for its diagnosis at its each stage.