Benidipine, an L-and T-type calcium channel blocker, dilates both efferent and afferent arterioles and reduces glomerular pressure. Thus, it may exert renoprotective effects. We conducted an open-labeled, randomized trial to compare the blood pressure (BP)-lowering effect and antiproteinuric effect of benidipine with those of amlodipine in hypertensive patients with moderate-to-advanced-stage chronic kidney disease (CKD) (stages 3-5). These patients were already being administered the current maximum recommended doses of angiotensin receptor blockers (ARBs). Patients with BP X140/90 mm Hg, despite treatment with the maximum recommended dose of ARBs, were randomly assigned to two groups. The patients received either of the following treatment regimens: 4 mg day À1 of benidipine, which was increased up to a dose of 16 mg day À1 (B group; n¼24), and 2.5 mg day À1 of amlodipine, which was increased up to a dose of 10 mg day À1 amlodipine (A group; n¼23). After 6 months of treatment, a significant and comparable reduction in the systolic and diastolic BP was seen in both groups. The decrease in the urinary protein to creatinine ratio in the B group was significantly lower than that in the A group. Benidipine exerted antiproteinuric effect to a greater extent than did amlodipine, even in patients with diabetic nephropathy. We conclude that the addition of benidipine, rather than amlodipine, ameliorates urinary protein excretion in hypertensive patients with CKD who are already being administered ARBs. Therefore, we propose a combination therapy with benidipine and ARBs, even for patients with moderate-to-advanced-stage CKD.