Herediatry myeloperoxidase deficiency present in the homozygous form in about 1.9000 individuals.Heterozygotes showing a quantitative decrease in neutrpphil MPO concentration are common.Although there is some debate , MPO deficiency does appear , by itself , to predispose to increased infection. However MPO deficient subjects with an underlying chronic disease such as diabetes , have a significant increase in the incidence of candida infections. Acquired myeloperoxidase deficiency which must be distinguished from the hereditary form is associated with leukemias and thrombotic disease We found this case in 9 years old boy by using H1 Hematology system