Blood pressure (BP) variability is calculated as the standard deviation of ambulatory BP. Blood pressure variability is associated with the cardiovascular morbidity; however whether it is related to target organ damage is controversial. In this study we examined a possible relationship between the BP variability and left ventricular hypertrophy (LVH), and between BP variability and brachial-ankle pulse wave velocity (baPWV). The present study was conducted on 111 consecutive Japanese hypertensive patients who were hospitalized for the educational program in our hospital under stable sodium chloride intake (6 g/day). Blood pressure measurements were at 30-minute intervals all day. In a multivariable analysis adjusted with confounding factor, LVH was associated with 24-hour systolic BP (SBP), 24 hour diastolic BP (DBP), daytime SBP, daytime DBP, nighttime SBP, and nighttime DBP. Additionally, nighttime DBP variability was related to LVH. By the same method, baPWV as a dependent variable was related to 24-hour SBP and nighttime SBP. Furthermore, nighttime SBP variability was concerned with baPWV. The LVH was associated with not only BP level but also with nighttime DBP variability. The baPWV was also related not only to BP level but also to nighttime SBP variability.