Abstract : Diabetes mellitus is a group of metabolic disorders characterized by lack of blood glucose homeostasis. This results from defects in insulin secretion, insulin action, or both. Optimal glycemic control is fundamental in the management of DM. It is considered the main therapeutic objective for preventing the development and progression of diabetic micro and macro vascular complications. The aim of this study is to assess the glycemic control of diabetic patients by the correlation between FPG and PPG with HbA1c. More than 40 original research articles using online database were critically reviewed. It was found that the correlation between PPG and HbA1c is stronger than that between FPG and HbA1c. However, some studies revealed a stronger correlation between FBG and HbA1c than that between PPG and HbA1c. The correlation coefficient (r) ranged from 0.44-0.81 for PPG and from 0.28-0.81 (Table 1). Patients who achieved 2-h PPG within the reference limit better attained target HbA1c values than patients who achieved FPG within reference limit. In other words, decreasing PPG accounted for a greater decrease in HbA1c than decrease in FPG. Therefore, control of PPG is more reliable for achieving target HbA1c ˂7% than FPG. Both FPG and PPG levels were correlated with HbA1c, but higher correlation was observed between HbA1c and PPG than FPG. HbA1c is the best standard in assessing glycemic control with the availability of standardized methods