The effects of calcium channel blockers (CCBs) and angiotensin converting enzyme (ACE) inhibitors on blood pressure and the progression of renal dysfunction were compared in hypertensive patients with polycystic kidney disease (PKD). Twenty-six patients with PKD and hypertension who had been treated with other antihypertensive agents, such as diuretics, beta-blockers, or alpha-methyldopa, were followed up for two years, during which their blood pressure and renal function were monitored. Patients were divided into two groups classified according to the type of antihypertensive agents given. Group 1 (n = 14) received CCBs, while group 2 (n = 12) received ACE inhibitors. No significant differences were found in their blood pressure control and serum creatinine levels throughout the study. The creatinine clearances were decreased in both groups. However, the decreases in creatinine clearance were smaller (p < 0.05) in the group treated with CCBs. In addition, two patients in group 2 showed rapid increases in serum creatinine. Our data suggest that CCBs reduced blood pressure effectively and preserved renal function in PKD patients at least as well as ACE inhibitors.