Background: Masked hypertension (MH) has been drawing attention recently because this condition is often seen in untreated and treated individuals and is associated with target organ damage and a poor cardiovascular prognosis. Arterial stiffness is associated with organ damage in patients with primary hypertension. The aim of this study was to evaluate pulse wave velocity (PWV) in MH and true hypertension (TH). Methods: We enrolled 146 patients (mean age 47.9±13.9 yrs, male 78 (53.4 %)), who was recently diagnosed as hypertension. MH was defined as office normotension (systolic blood pressure(SBP)