The relative efficacies of 240 mg/day diltiazem and 20 mg/day nitrendipine were compared in a placebo-controlled, randomized, crossover study of 48 patients who had both moderate systemic hypertension and stable angina pectoris. Hemodynamic indices were measured by impedance cardiography and echocardiography and bicycle ergometry was performed. Compared with placebo, both diltiazem and nitrendipine decreased systolic (p < 0.05 for both) and diastolic (p < 0.05 for both) blood pressure, the total peripheral vascular resistance (p < 0.01 for both), the frequency of anginal attacks (p < 0.001 for both) and nitroglycerin usage (p < 0.01 for both), and increased exercise duration (p < 0.01 and p < 0.05), exercise time to angina (p < 0.01 and p < 0.05) and time to the onset of ST-segment deviation (p < 0.01 and p < 0.05). There were no significant differences in the antihypertensive and antianginal effects of the two drugs. Resting heart rate was increased from placebo baseline with nitrendipine (p < 0.01) during the first week of the treatment, and the reduction of the rate-pressure product and the decrease of the left ventricular mass were greater using diltiazem (p < 0.05). Sixteen patients had insufficient responses to monotherapy and continued in the study for additional treatment with the combination 120 mg/day diltiazem and 20 mg/day nitrendipine. The normalization of diastolic blood pressure was achieved and more pronounced rate-pressure product reduction was found. No additional side effects were mentioned. Diltiazem and, especially, the combination of diltiazem and nitrendipine is an effective and safe therapy for patients with both systemic hypertension and stable angina pectoris.