To investigate the safety and efficacy of endovascular therapy with combined intra-arterial and intravenous thrombolysis for severe cerebral venous sinus thrombosis. Of the 28 consecutive patients with cerebral venous sinus thrombosis admitted to our hospital in recent 3 years, six patients underwent combined intra-arterial and intravenous thrombolysis. For each patient, local contact thrombolysis was performed with balloon catheter to break clot and urokinase infused for thrombolysis in sinus. At the same time, urokinase (100,000 IU/h) was infused intra-arterially via internal carotid artery to dissolve the venous thrombi. Neurologic outcomes, Glasgow coma scale (GCS), neuroimaging results and modified Rankin Scale score (mRS) were recorded. Of the six treated patients, two were males and four females. Their mean age was 38 +/- 13 (range from 22 to 57) years. Completely recanalization was observed in five patients, whose clinical symptoms recovered completely (mRS score 0). One patient in whom thrombolysis was delayed died the day after the procedure. Endovascular treatment with combined intra-arterial and intravenous thrombolysis may improve neurological outcomes of severe cerebral venous sinus thrombosis.