Hereditary hypercoagulability has been identified as risk factor in approximately 30% of cerebral venous thrombosis cases. We report three females with this association. A 38 years old female with a history of deep venous thrombosis of the lower limb, presented with headache, vomiting and a generalized seizure. Magnetic resonance angiography showed a partial thrombosis of the left lateral and superior longitudinal venous sinuses. Coagulation study showed a resistance to activated C protein and factor V Leyden. A 42 years old woman with a history of deep venous thrombosis, presented a right hemiplegia during a hospitalization. Magnetic resonance showed a left lateral hemorrhagic infarction. Magnetic resonance angiography showed an absence of signal in three venous sinuses. Coagulation study showed a protein C deficiency. A 17 years old woman presented a right hemiparesis in the sixth day of puerperium. CAT scan showed a left frontoparietal subcortical venous infarction. Coagulation study showed an antithrombin III deficiency (Rev Méd Chile 2002; 130: 79-85)