The ability of neutrophils to phagocytose and kill Candida guilliermondii was investigated in 28 pregnant women and compared with 29 healthy controls. Phagocytosis was normal, but the ability to kill and digest Candida was reduced to 65% of normal. Quantitative myeloperoxidase measurement revealed a considerable reduction of this enzyme (55% of normal) while neutrophil alkaline phosphatase levels were nearly twice as high as in normals. It is suggested that both lack of myeloperoxidase and impaired candidacidal ability result from the discharge of the neutrophil's granules during previous phagocytosis of antibody—antigen complexes in the circulation.