Deep cerebral venous system thrombosis is uncommon and is usually encountered in children, generally in the neonatal period. In adults, this pathology is even more exceptional. We report two cases in adults. Deep cerebral venous system thrombosis mainly affects women taking oral contraception. The most common clinical pattern combines headaches and confusion. A comatose state is rather exceptional. This pathology, formerly considered to have poor prognosis, has benefited from diagnostic and therapeutic progress. Favorable outcome has been achieved in several recent cases, as one of ours, without after-effects. Diagnosis, often suggested by the CT-scan, is based on MRI associated with MRA. Thrombus formation is easily diagnosed by MRI at the subacute stage, but far less easily at the acute and chronic stages as the low signal is identical to the normal flow void. MRA, in phase contrast or time of flight sequences, is highly interesting at the acute phase. In case of doubt, an angiography can be applied. Therapy is based on heparin. The contribution of local infusion of thrombolytic agents, recently used with success, remains to be determined.