Glucose 6-phosphate dehydrogenase (G6PD) was purified from turkey erythrocytes by ammonium sulphate precipitation and followed by ADP Sepharose affinity gel chromatography. The yield was 49.71% and specific activity of the enzyme was found to be 44.16 EU/mg protein. By gel filtration the molecular mass was found to be 75 kDa. The enzyme had an optimum pH at 9.0, and optimum temperature at 50 degrees C. Km and Vmax for NADP(+) and glucose 6- phosphate (G6-P) as substrates were also determined and effects of inhibitors such as ATP, NADH and NADPH were examined.