Until recently, the effect of smoking as a risk factor in cerebral vascular events had not been analyzed carefully and no causal relationship had been identified. This could appear paradoxical since it has been well established that smoking plays a role in the pathogenesis of ischaemic cardiopathies and peripheral angiopathies. Indeed, several population studies have demonstrated that smoking plays a role in meningeal haemorrhage, but in other types of cerebral vascular events, biases related to the heterogeneous character of the involved mechanisms could explain the lack of any identifiable relationship. The most recent hospital series both in Europe and in North America based on case-control studies have however demonstrated that tobacco smoking is a vascular risk factor for most types of cerebral vascular events. Increased risk has been estimated between 1.7 and 5.7. While smoking habits in Western countries have declined, these findings emphasize the importance of the tendency towards an increased rate of cigarette smoking in third-world countries. In addition, from a public health standpoint, smoking is an extremely interesting aetiological factor since it is theoretically controllable.