Thrombosis of deep cerebral veins is a rare condition, and is associated with a poor prognosis. We report four new cases observed between 1994 and 1997. All four cases were women, aged less than 45 years. Initial symptoms associated alteration of consciousness, change in mental status, progressive headache and vomiting. We observed also uni or bilateral signs of long tract injury. In three cases, diagnosis initially suspected by CT scan was confirmed with encephalic MRI. For the last patient, conventional angiography was needed. Thrombosis affected straight sinus, vein of Galien and internal cerebral veins in all patients. Basilar veins were also affected in one patient, without dural sinuses extension. Lateral sinus was involved in two others cases, and superior sagittal in the last patient. Etiology remains undetermined in one patient, associated with post-partum, use of oral contraceptive pill, and familial protein S deficiency, one case each. Outcome was favorable in all four cases with anticoagulation therapy. Precocity of diagnosis is determinant and MRI is usefull in this issue. These observations show that evolution of deep veins thrombosis can be favorable, without needing fibrinolytic therapy.