Masked hypertension (MH) is associated with advanced target organ damage. However, patients with MH constitute a group of individuals with heterogeneous characteristics concerning their ambulatory blood pressure (BP) status. The aim of this study was to evaluate the association of isolated systolic MH, isolated diastolic MH, and systolic/diastolic MH with carotid artery intima-media thickness (CIMT). A total of 101 patients with MH underwent carotid artery ultrasonographic measurements. The patients were divided into three groups according to office and daytime BP values: isolated systolic MH, isolated diastolic MH, and systolic/diastolic MH. Patients with isolated systolic (n=36) (0.771 mm) and systolic/diastolic MH (n=37) (0.775 mm) had significantly (P<.05) higher CIMT values than those with isolated diastolic MH (n=28) (0.664 mm), even after adjustment for baseline characteristics and risk factors. Patients with isolated systolic and systolic/diastolic MH presented significantly higher CIMT values compared with patients with isolated diastolic MH.