Background : Measurement of blood glucose is a basic part of patient care. Increasingly, blood glucose measurement has become a part of self-care. Devices featuring convenience and quickness are used to measure blood glucose and are used in settings often unsupervised by knowledgeable health care personnel. In this context, a validation test of a handy assurances that the devices that they are using or purchasing are capable of producing valid results. Method : In this study, we fulfilled requirements from the ICH Q2 guidelines for assurance of accuracy, precision, linearity and range. From the two subjects, blood glucose was measured repeatedly at post-prandial 1h/2h/3h/4h, 12 times each, by two investigators and with two instruments. Then, we compared the results of a handy blood sugar measuring instrument with those of a chemistry analyzer, Hitachi 7070 auto-analyzer, in a core laboratory in Clinical Trial Center, Seoul National University Hospital. Results : Mean accuracy, intra-assay precision and intermediate precision were 92.6%, 2.3%(min. 1.07%, max. 4.51%), 1.73%(min. 0%, max. 5.65%) each. In scatter plot of the results of a handy blood sugar measuring instrument and Hitachi 7070 auto-analyzer, linearity was apparent and the correlation coefficient(r), $r^2$ was 0.986 and 0.972 each. Conclusions : Mean accuracy was not satisfactory regarding the criteria for quality control of blood glucose $measurement(within {pm}5%)$ in SNUH. The intermediate precision was also not satisfactory regarding the criteria for Quality Control (less than 5%).