We aimed to explore whether diurnal blood pressure (BP) peak characteristics have a significant influence on the association between left ventricular damage with the two BP components (morning BP vs. afternoon peak BP) in untreated hypertensives. This cross-sectional study included 1084 hypertensives who underwent echocardiography and 24-h ambulatory BP monitoring. Participants were stratified according to the relationship between morning systolic BP (MSBP; average SBP within 2 h of waking up) and afternoon peak systolic BP (ASBP; average SBP between 16:00 and 18:00). Afternoon and morning hypertension was defined as ≥ 135/85 mm Hg. The morning and afternoon peak BPs occurred at around 7:00 and 17:00, respectively. In general hypertensives, morning BP and afternoon peak BP are significantly different in absolute values (for binary SBP, McNemar's χ2  = 6.42; p = .014). ASBP was more pronounced than MSBP in 602 patients (55.5%), in whom 24-h SBP showed higher consistency with ASBP than with MSBP (Kappa value: 0.767 vs 0.646, both p < .01). In subjects with ASBP ≥ MSBP, ASBP was associated with left ventricular hypertrophy independent of MSBP (logistic regression analysis odds ratio: 1.046, p < .01), and left ventricular mass index was more strongly correlated with ASBP than with MSBP (multiple regression coefficient β: 0.453, p < .01), in which the relationships held true independently of 24-h SBP. The opposite results were obtained in subjects with MSBP > ASBP. Peak BP-guided monitoring may serve as an effective approach to out-of-office hypertension monitoring and control, providing the best consistency with 24-h average SBP and highest discrimination performance for target organ damage, independently of 24-h SBP.