Human polymorphonuclear leukocytes (PMNL) can metabolize [1-14C]2-deoxyglucose to 14CO2 when stimulated by either phorbol myristate acetate (PMA) or opsonized zymosan. Oxidation of 2-deoxyglucose is about 10-120% as efficient as that of glucose in normal PMNL; it does not occur in defective cells obtained from patients with chronic granulomatous disease. The increased oxidation of [1-14C]2-deoxyglucose induced by PMA is not sufficient to explain the inhibition of transport induced by that compound; conversely increased transport of 2-deoxyglucose induced by zymosan-activated serum does not result in a significant increase in oxidation of the hexose. Oxidation of [1-14C]2-deoxyglucose appears to be mediated by the hexose monophosphate shunt as indicated by the following (1) oxidation of [1-14C]2-deoxyglucose in intermediate in activity between that of [1-14C]glucose and [6-14C]glucose; (2) the reaction is insensitive to cyanide or azide; and (3) shunt enzymes measured in a cell-free extract from human PMNL can react with 2-deoxyglucose compounds with approximately 10% the efficiency shown towards the corresponding glucose derivatives.