Hypertensive subjects can be subdivided into 2 groups, dippers and nondippers, according to the presence or the lack of a nocturnal fall of blood pressure of more than 10%. Several studies have investigated cardiac organ damage in the 2 groups with discordant results, but they included subjects with different onset, severity, and treatment of hypertension. The authors selected 23 dippers and 17 nondippers affected by newly (< 1 year) diagnosed grades 1 and 2 hypertension, never treated, who underwent 24-hour ambulatory blood pressure monitoring and M-mode echocardiography. They did not find significant differences between the 2 groups as regards the echocardiographic left ventricular and atrial dimensions or regarding the left ventricular mass, left ventricular mass index, or relative wall thickness. Also no significant differences were found in the rate of either left ventricular remodeling or left ventricular hypertrophy. These data suggest that nondipping status is not associated with a higher level of cardiac involvement in the early phases of hypertension compared to dipping status.