In the present study, blood samples from 1183 children aged 0.5-6 years were taken. Three children were found with G6PD deficiency by examining the enzyme activity and hemoglobin ratio. Some kinetic properties of glucose 6-phosphate dehydrogenase enzyme (G6PD) were studied after the purification of the enzyme with ammonium fractionation, dialysis and 2',5' ADP-Sepharose 4B affinity chromatography from a healthy person and from three G6PD-deficient people. The purity of the enzymes was confirmed by SDS-PAGE electrophoresis. The effects of some drugs which are known inhibitors of G6PD activity were studied. Some of the drugs stimulated the activity of the enzyme in two of the three cases with G6PD deficiency. K-M values, V-max values for G6P and NADP(+), optimum pH and optimum temperature for the enzyme from the healthy person and the three G6PD-defficient people are reported.