The determination of glucose in hemolysed and stabilized blood samples by the hexokinase/glucose-6-phosphate-dehydrogenase-method is described. The glucose concentration in hemolysed blood samples was stable for 7 days. Even at high glucose concentrations (linear range up to 60 mmol/l), the reaction came to completion within 5 minutes. No interference by lipemia, bilirubin and drugs was observed; the interference of fructose was slight. Compared with deproteinized samples there was a very good correlation between this method and the reference method. Precision and recovery were good. This method is also suited for the analysis of few samples and offers the possibility of blood sugar self-profiles in diabetic out-patients and gives an increasing improvement of diabetic control.