Background: The present cross-sectional study was aimed to identify pre-hypertension and masked hypertension rate in clinically normotensive adults in relation to socio-demographic, clinical and laboratory parameters. Methods: A total of 161 clinically normotensive adults with office blood pressure (OBP) <140/90 mmHg without medication were included in this single-center cross-sectional study. OBP, home BP (HBP) recordings and ambulatory BP monitoring (ABPM) were used to identify rates of true normotensives, true pre-hypertensives and masked hypertensives. Data on sociodemographic and clinical characteristics were collected in each subject and evaluated with respect to true normotensive vs. pre-hypertensive patients with masked hypertension or true pre-hypertensive. Target organ damage (TOD) was evaluated in masked hypertensives based on laboratory investigation. Results: Masked hypertension was identified in 8.7% of clinically normotensives. Alcohol consumption was significantly more common in masked hypertension than in true pre-hypertension (28.6 vs. 0.0%, p = 0.020) with risk ratio of 2.7 (95% CI 1.7-4.4). Patients with true pre-hypertension and masked hypertension had significantly higher values for body mass index, waist circumference, systolic and diastolic OBP and HBP (p < 0.05 for each) compared to true normotensive subjects. ABPM revealed significantly higher values for day-time and night-time systolic and diastolic BP (p = 0.002 for night-time diastolic BP, p < 0.001 for others) in masked hypertension than true pre-hypertension. Conclusions: Given that the associations of pre-hypertension with TOD might be attributable to the high prevalence of insidious presentation of masked hypertension among pre-hypertensive individuals, ABPM seems helpful in early identification and management of masked hypertension in the pre-hypertensive population.