Résumé : Chronic alcohol abuse is responsible for several organic brain disorders. However, even the most characteristic of them are largely underdiagnosed by routine procedures. Therefore, there is need for sensitive, noninvasive and low-cost diagnostic procedures. 99m-Tc-HMPAO-SPECT could be an interesting candidate in this indication, because it estimates the distribution of the cerebral blood flow and the metabolic activity of the brain with a good resolution. We used this technique in 17 healthy volunteers and in a sample of 50 patients dependent on alcohol, without other major physical or mental disorder. SPECT was performed during the attendance of these patients in an inpatient detoxification program. We observed abnormal SPECT in 34 patients, but only in 2 volunteers (p < 0.001). The main abnormality was heterogeneity of the distribution of the tracer. SPECT abnormalities appear to be due nor to withdrawal syndrome, nor to medication. On the contrary, they are correlated with stigmata of heavy alcoholism. Furthermore, a genetic vulnerability to alcohol was suspected because SPECT abnormalities are more frequent in patients with an history of drinking problems in their relatives.