Aim: Generally, the level of glycoalbumin (GA) is approximately 3 times higher than that of HbA1c. However, in type 1 diabetic patients, we often find an even higher GA/HbA1c ratio of nearly 3.5. Therefore, this study was performed to examine the significance of a higher GA/HbA1c ratio. Methods: 17 type 1 diabetic patients were enrolled in part 1 of the study and divided into two groups, one with a higher and the other with a lower GA/HbA1c ratio. In both groups, the correlation between GA or HbA1c level and each “4-point” capillary glucose level was analyzed. 80 type 1 diabetic patients were enrolled in part 2 of the study and the relationship between mean GA/HbA1c ratio in the past year and degree of diabetic retinopathy was analyzed. Results: In part 1 of the study, we found positive correlations between GA and bedtime capillary glucose levels and between HbA1c and bedtime capillary glucose levels in the higher GA/HbA1c group (r = 0.86, p = 0.023; r = 0.95, p = 0.012, respectively), but not in the lower GA/HbA1c group. In part 2 of the study, a significant positive correlation between GA/HbA1c ratio and severity of retinopathy could be observed (r = 0.269, p = 0.017). Conclusion: A higher GA/HbA1c ratio may reflect a postprandial hyperglycemic state and simultaneous monitoring of GA and HbA1c may improve the management of diabetic patients.