The antianginal efficacy of niludipine (Bay a 7167), a new calcium antagonistic drug, was investigated in 51 patients with ischemic heart disease. 16 patients were diagnosed as effort angina and 31 patients had both angina at rest and on effort. Six anginal patients had myocardial infarction. One patient was diagnosed as a variant form of angina and 3 others as unstable angina. 11 patients had essential hypertension. 49 completed the study and 2 dropped out. Niludipine (60 mg to 80 mg every 24 h) significantly reduced the mean weekly rate of angina attacks from 6.5 to 2.2 (p less than 0.001). Marked reductions of nitroglycerin requirement were also noted (p less than 0.001). In 71% of the patients complete control of anginal attacks was achieved, and in over 77% the frequency of angina was reduced by at least 50%. Niludipine was at 93.8% effective in patients with ischemic heart disease. It decreased significantly both systolic and diastolic blood pressure in angina patients with essential hypertension, but there were no significant changes of blood pressure in normotensive anginal patients. The agent was tolerated very well and there were no side effects. These findings suggest that niludipine is a highly effective drug for the treatment of both ischemic heart disease and essential hypertension.