Erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, usually designated as "primaquine sensitivity," is a common genetic disorder of wide geographic and racial distribution.1,2 It occurs in 12% to 15% of male Negroes and also in certain Caucasian population groups, eg, Sephardic Jews, Sardinians, Iranians. Enzyme activity is usually not completely absent, and, therefore, persons with this abnormality are ordinarily not anemic unless hemolysis is provoked by the exposure to certain toxic and infectious agents.1,2 Complete absence of G-6-PD activity in the red cell is very rare. It has been described in children,3-5 usually of Northern European extraction, with nonspherocytic hemolytic anemia. There have been very few references 4,6 to the existence of this variant of G-6-PD deficiency in the adult. The hemolytic process due to this disorder may not become clinically manifest until adult life, and, therefore, its occurrence in the older age groups needs to be emphasized. The