One hundred and thirty-eight cases of cerebral venous/venous sinus thrombosis during the puerperium have been studied. Maximum number of cases (112 cases) occurred in the age below 30 years. Signs and symptoms appeared in most of the cases (72 cases) during the first 7 days of post partum period. One hundred and eleven cases were multipara. Commonest signs and symptoms were fever (85 cases); headache (66 cases), convulsions (64 cases), altered consciousness (57 cases), hemiplegia (60 cases), papilloedema (48 cases), etc. Carotid angiography done in 55 cases revealed block in middle part of superior sagittal sinus in 24, and localised, dilated and tortuous cortical veins in 5. A statistically significant rise in serum triglycerides, phospholipids, free fatty acids, blood platelet count, platelet adhesive index, and fall in blood fibrinolytic activity were found as compared with normals. These factors may be playing a role in the etiology of cerebral venous/venous sinus thrombosis during puerperium.