IntroductionHypertension is a significant health problem due to its high prevalence and associated risks of cardiovascular, cerebrovascular and renal complications (1) In a significant number of patients, control of hypertension is difficult, despite effective therapeutic strategies (2,3). Pickering et al. (4) initially determined the phenomenon of masked hypertension (MH) to describe the clinical condition of patients with elevated ambulatory blood pressure (ABP) but normal clinical blood pressure (CBP). Most of these patients were unaware of their blood pressure status and therefore did not receive antihypertensive therapy (4). These MHT patients had target organ damage, such as albuminuria and left ventricular hypertrophy. In fact, the risk of cardiovascular disease is even higher in HD patients than in patients with essential hypertension (4). MHT is a public health problem due to the confluence of increased CVD risk, an inability to diagnose with the conventional approach of blood pressure measurement in clinical settings, and a relatively high prevalence (5,6, 7,8). According to the landmark SHEAF study, HD patients are at increased risk of developing sustained hypertension (9,10). Masked hypertension (MHT) is clinically defined in nondiabetics as blood pressure (BP) levels less than 140/90 mmHg. and daytime blood pressure > 135/85 using ambulatory blood pressure monitoring (ABPM) and in patients with diabetes as OBP 125/75 mmHg (11). The prevalence of MHT is accepted to be around 8-10% in the general population. Among the diabetic population, the prevalence of masked hypertension has increased two to six times compared to the general population. In current literature, MHT is associated with increased macrovasculature and microvasculature... half of article......5 require intensive regulation of blood pressure to prevent target organ damage. Limitations of the study The number of diabetic patients in this study is limited, because as a tertiary center the diabetic patients referred to our institution were complex patients and most of them had overt hypertension. The second limitation of our study is that we could not perform an analysis to determine factors of masked hypertension other than poor glycemic control, due to the limited number of patients. Conclusion The incidence of masked hypertension is increased in diabetic patients, especially with elevated HbA1c levels, although it is not statistically different from that of patients with HbA1c levels >6.5 who had higher blood pressure measurements in ABPM . T2DM patients with potentially high risk of clinical cardiovascular disease and hypertension-induced target organ damage should be definitively evaluated for MH.