The authors examined the effect of cilnidipine, a unique L/N-type calcium channel blocker, on abnormal nocturnal blood pressure (BP) dipping in Japanese hypertensive patients in the real world. The Ambulatory Blood Pressure Control and Home Blood Pressure (Morning and Evening) Lowering by N-Channel Blocker Cilnidipine (ACHIEVE-ONE), a large-scale clinical study, was designed to evaluate the effects of cilnidipine in daily medical practice. Among the study, 24-hour ambulatory BP data were obtained from 615 patients and classified according to their nocturnal dipping status as extreme dippers, dippers, nondippers, or risers. A 12-week treatment with cilnidipine significantly reduced 24-hour BP in all groups (P<.001). Changes in nocturnal systolic BP (SBP) from baseline were −17.9 mm Hg from 154.6 mm Hg in risers and −11.9 mm Hg from 142.1 mm Hg, −6.6 mm Hg from 128.5 mm Hg, and 0.1 mm Hg from 115.8 mm Hg in nondippers, dippers, and extreme dippers, respectively. Changes from baseline in nocturnal SBP reduction rate were 8.2% in risers (P<.001) but −7.0% in extreme dippers (P<.001), while no change was observed in the nighttime SBP reduction rate for the total patients (−0.2%±9.6%, P=.617). Cilnidipine partially, but significantly, restored abnormal nocturnal dipping status toward a normal dipping pattern in hypertensive patients.