Neuropathological study of brain and brain vessels was performed in two series of 12 and 20 centenarians, focusing on the prevalence of small vessel lesions, infarction, Alzheimer's changes and mental status. These are discussed as a function of vascular risk factors. In the first series (12 cases), there was no correlation between the severity of small vessel lesions: hyalinosis (12/12), mineralisation (10/12), amyloid angiopathy (9/12), vascular risk factors (high blood pressure or diabetes), Alzheimer's lesions. However, there was a tendency for an association between amyloid angiopathy and high density of neurofibrillary tangles. In the second series (20 cases), small infarcts and lacunes were found in 9/20 cases, neurofibrillary tangles and diffuse deposits of A beta peptide were constant, senile plaques were very frequent (19/20). Five patients were demented (one vascular dementia, one Alzheimer dementia, and 3 mixed dementias). These data indicate that: 1) Lesions of the walls of small cerebral vessels do not seem linked to the vascular risk factors observed at the end of the life of centenarians. 2) Cerebral infarcts and lacunes are frequent in these patients, and are responsible, at least in part, for a high proportion of the cognitive dysfunctions. The study of larger series is needed for a better understanding of relationships between vascular and degenerative lesions in the oldest old.