Abstract: Glucose 6-phosphatase dehydrogenase (G6PD) is the key enzyme of the hexose monophosphate pathway. In uremic subjects, red blood cells exhibit reduced life spans and are very often the main factor behind the physical activity limitation of the patients. This study was conducted to determine the effect of uremia on GGPD activity and if there is any relationship between the effect of enzyme activity and the number of RBCs by measuring Hb. Also, the study aimed to elucidate the effect of a single dialysis session on G6PD.