We evaluated whether morning minus evening systolic blood pressure (SBP) difference (MEdif) in home blood pressure measurements can be a marker for hypertensive target organ damage. The authors analyzed 611 hypertensive patients who had high morning SBP levels (>/=135 mm Hg). The patients with morning hypertension (MEdif >/=15 mm Hg, average of morning and evening SBP [MEave] >/=135 mm Hg) were older (P<.001) and had a longer duration of hypertension and antihypertensive medication use, a higher prevalence of left ventricular hypertrophy (LVH) on electrocardiography, a lower glomerular filtration rate by the Cockcroft-Gault equation (P=.002), and a higher brain natriuretic peptide (BNP) level (P<.001) than those with well-controlled blood pressure (MEdif <15 mm Hg, MEave <135 mm Hg). The patients with morning hypertension had a higher BNP level than those with well-controlled blood pressure after adjustment for the confounding factors (28.7 pg/mL vs 20.0 pg/mL; P=.033). In conclusion, morning hypertension is more likely seen among patients with older age and longer duration of hypertension and antihypertensive medication use, and it may be associated with a higher prevalence of LVH and a higher BNP level.