High-dose calcium channel blocker (CCB) shows strong blood pressure (BP) lowering effect. Currently available of controlled-release (CR) nifedipine 80 mg per day clinical data are limited to monotherapy and short-term or long-term retrospective studies. We report the safety and efficacy results of a 52-week, prospective open-label study, in which Japanese patients with essential hypertension were treated with CR nifedipine [80 mg per day; 40 mg bis in die (BID; twice daily)] in combination with other antihypertensive drugs. The patients with inadequate BP control despite treatment with CR nifedipine (40 mg once daily) in combination with other antihypertensive drugs were enrolled. The primary objective of this study was to assess the long-term safety of CR nifedipine (80 mg per day). Efficacy variables included changes in the mean sitting BP, the target BP achievement rate and the BP response rate. CR nifedipine (80 mg per day) was generally well tolerated, with the most common drug-related treatment-emergent adverse event being tachycardia (6.9% of patients). Serious treatment-emergent adverse events were reported in three (4.2%) patients. By week 52, the mean reductions in sitting systolic and diastolic BP were 19.4 and 13.6 mm Hg, respectively. The target BP achievement and BP response rates after 52 weeks of treatment were 32.4 and 63.4%, respectively. Based on these findings, long-term treatment with CR nifedipine at 40 mg BID in combination with antihypertensive drugs was well tolerated and effective in Japanese patients with essential hypertension.