Nifedipine was evaluated in the management of eight patients with intractable coronary arterial spasm. All had Prinzmetal's variant angina, normal or mildly abnormal coronary arteriograms, and a positive ergonovine maleate provocative test. Anginal attacks occurred at least three times a week in all patients during isosorbide dinitrate therapy. All patients had a decrease in frequency of ischemic attacks with nifedipine. Seven patients underwent repeat Holter monitor evaluation, which confirmed the absence of ischemic changes while they were taking nifedipine. When nifedipine dosage was decreased.or therapy discontinued in six patients, all experienced a recurrence of anginal attacks. Two patients had minor side effects, which required a decrease in the dose of nifedipine. Nifedipine was well tolerated, and no major complications occurred with its use. Nifedipine appears to be effective in the management of patients with symptomatic coronary arterial spasm and normal or mildly abnormal coronary arteriograms. Our data justify further investigation of nifedipine for treatment of such patients.