30 patients clinically suspected of suffering from venous sinus thrombosis were examined by MRT with venous MR angiography (FLASH 2-D). In 8 patients selective arterial angiography was also performed and 5 patients were followed up by MR angiography after an interval of three months. The MRT images and individual MR angiography images were analysed and 3-D reconstruction performed. In 11 patients MR angiography correctly demonstrated venous sinus thrombosis; the most frequently affected were the superior sagittal sinus, the ascending cerebral veins and the transverse sinus. Compared with DSA, magnetic resonance angiography achieved a high degree of accuracy in our patients. It was significantly better in evaluating the basal sinus system whereas thrombosis of individual ascending veins was better shown by DSA. In summary, primary use of MRT and MR angiography is recommended for the diagnosis of venous sinus thrombosis.