Following a survey on prevalence of sickle-cell anemia in Brazzaville's Region, the authors surveyed, in the same population, the incidence of Glucose-6-Phosphate dehydrogenase deficiency (G6PD) and the sharing of enzyme deficiency among sickle cell anemia patients (AA). This survey was carried out among children from 0 to 3 years of age, thanks to a very close collaboration between the Laboratory of bio-chemistry of the Faculty of Sciences, Maternity Hospitals of Blanche-Gomez, Makelekele, and Maternity Ward of the Brazzaville General Hospital. 214 children were examined in these Health Units. Blood samples were analysed by the thin layer isoelectric focusing technics. 128 children were safe from hemoglobin abnormalities, 44 had heterozygous and 42 homozygous sickle cell anemia, i.e. 19.6 p.c. of the total population surveyed. Measurement of the G6PD activity in these children revealed that 25.8 p.c. of the AA had an incomplete deficiency in G6PD, 31.8 p.c. of the AS and 45.2 p.c. of the SS were G6PD deficient (table I). These results, although fragmentary, demonstrate that G6PD deficiency does exist in the Congolese population, and that this enzyme deficiency might be more frequent in the carriers of sickle cell trait, evaluated by the authors at 22.4 p.c. of the population.