Se estudiaron 35 pacientes adultos con anemia drepanocítica. Se establecieron 2 grupos: grupo 1: 24 enfermos sin antecedentes de crisis del sistema nervioso central (15 hombres; 9 mujeres) y grupo 2: 11 casos con antecedentes de crisis (6 hombres; 5 mujeres). El promedio de edad fue de 31 años en el sexo masculino y de 29 años en el femenino. Todos los enfermos estaban en condiciones basales. El tiempo transcurrido entre la crisis y el estudio fue de 4,7 años. No hubo diferencia significativa en las cifras de hemoglobina y los reticulocitos entre ambos grupos. Se encontró aumento significativo de la velocidad sanguínea cerebral en todos los pacientes del grupo 1 y del grupo 2 (p 35 adult patients with drepanocytic anemia were studied. They were divided into 2 groups: group 1 was composed of 24 patients without history of central nervous system crisis (15 males and 9 females), whereas group 2 included 11 cases with crisis history (6 males and 5 females). Average age was 31 years old for males and 29 for females. All the patients were under basal conditions. The time elapsed between the crisis and the study was 4.7 years. No significant differences were observed between the hemoglobin figures and the reticulocytes of both groups. A marked increase of the brain blood velocity was found in all the patients from group 1 and group 2 (p < 0.05 y p < 0.001, respectively). In 13 patients from group 1 (54.1 %) the brain blood flow presented modifications, whereas it was altered in all patients from group 2. In 13 cases from group 1 (76.4 %) the electroencephalogram was normal, but it was altered in 87.5 % of the patients from group 2. In 4 patients from group 1 (23.5 %), the brain electrical activity showed some modification. Computerized axial tomography was normal in 19 patients from group 1. Some alteration was detected in 3 cases from group 2 (37.5 %).