We describe a rare case of superior sagittal sinus thrombosis in a young man (26 years) with undiagnosed ulcerative colitis. The patient was hospitalized with headache and paresis of the right arm and leg. he had had rectal bleeding and diarrhea for the previous 4 weeks. Despite the fact that heparin therapy is still considered controversial, we successfully treated our patient with low doses of sub-cutaneous heparin. He did not suffer any side-effect.