Oral contraceptive (OC) use is associated with an increased risk of cerebral thrombosis. However, the risk decreases with decreasing estrogen and progestogen dosage, and is not demonstrable for progestogen-only OCs. The risk estimates found in newer studies are substantially lower than those demonstrated for the OC brands used in the 1960s and 1970s.The relative risk of thrombotic stroke among users of OCs compared with non-users (i.e. never users plus ex-users) is about 1.5 and does not change with increasing age. The absolute risk, on the other hand, increases nearly exponentially with increasing age. For a 20-year-old healthy woman, the absolute risk of a cerebral thrombosis is about 2 per 100 000 individuals per year. The attributable risk from using OCs containing 30 to 40μg of estrogen is about 1 per 100 000 per year, corresponding to a total risk of 3 per 100 000 per year - still a very low risk. The type of progestogen in OCs has no influence on the risk of thrombotic stroke. OC use does not confer an increased risk of intracerebral haemorrhage.