Background: The present survey aimed to find out the demographical and clinical characteristics of patients with hypertension in a population with type 2 diabetes mellitus (T2DM) in Turkey. Methods: Patients with T2DM who were followed-up in tertiary endocrine units for at least last one year were recruited. Demographic, clinical and biochemical data of the patients were collected. Hypertension was defined as taking anti-hypertensive medications or having office arterial blood pressure (ABP) ≥140/90 mmHg or home ABP ≥ 130/80 mmHg. Results: A total of 4756 (58.9% women) diabetic patients were evaluated. The percentage of patients with hypertension was 67.5% (n = 3212). Although 87.4% (n = 2808) of hypertensive patients were under treatment, blood pressure was on target in 52.7% (n = 1479) of patients. Hypertension proportions were higher in woman (p = 0.001), older, more obese, and those who had longer diabetes duration, lower education levels, higher frequency of hypoglycemic events (all p < 0.001) and higher triglyceride levels (p = 0.003). LDL cholesterol level and the percentage of smokers were lower in hypertensive group than in non-hypertensive group (both p < 0.001). The percentage of macro and microvascular complications was higher in the hypertensive group than in the normotensive one (both p < 0.001). In multivariate logistic regression analysis, being a woman (OR: 1.26, 95% CI: 1.04–1.51, p = 0.016), smoking (OR: 1.38, 95% CI: 1.05–1.80, p = 0.020), regular physical activity (OR: 1.24, 95% CI: 1.01–1.53, p = 0.039) and the presence of macrovascular complications (OR: 1.38 95% CI: 1.15–1.65, p = 0.001) were the significant predictors of good ABP regulation. The ratios of masked and white coat hypertension were 41.2% and 5.7%, respectively. Conclusion: Our findings indicate that two-thirds (67.5%) of adult patients with T2DM have hypertension. Co-existence of hypertension increases the frequency of macro and microvascular diabetic complications in these patients. Despite the critical role of hypertension in morbidity and mortality, only half of the patients have favorable ABP levels. Masked hypertension seems to be another important issue in this population.