A hereditary thrombophilia is found in 20-30% of patients with cerebral venous thrombosis (CVT). These patients might have an increased rate of a positive personal or family history of venous thrombotic events. We investigated the diagnostic value of a structured personal and family history for venous thrombotic events in 56 consecutive cases of CVT. Fourteen of 56 patients (25%) had a hereditary thrombophilia, mostly factor V Leiden. Patients with both CVT and hereditary thrombophilia had more frequently a positive family and personal history than patients affected by CVT only but the difference was not strong enough to differ from the 42 CVT patients without thrombophilia (43% vs. 31%; P = 0.52 and 14% vs. 10 %; P = 0.63). We conclude that a negative personal and family history of venous thrombotic events is not sufficient to exclude thrombophilia and patients with CVT should be tested for inherited thrombophilia regardless of the patient's past personal and family history for venous thrombotic events.