We evaluated a slight modification of the automated oxidase/peroxidase method for glucose determination in blood with use of 4-aminophenazone [J. Clin. Pathol. 22, 246 (1969)]. Nonsugar reducing substances did not interfere, except for ascorbic acid in very high concentrations. Lipemic sera gave slightly lower values. Values for reproducibility, specificity, and sensitivity were closer to such values for the hexokinase method than was the case for some other commonly used methods.