The effects of isosorbide dinitrate single dose 120 mg daily and nifedipine 20 mg twice daily were studied in 17 patients with variant angina pectoris due to coronary artery spasm. After a placebo phase the patients were randomized to treatment with either isosorbide dinitrate or nifedipine. After six weeks the patients were crossovered for another six weeks period of treatment. There was significant decrease of number of angina attacks during both treatment regimens. Using 24 hours Holter monitoring we also proved significant decrease of number of ST segment elevation or depression, either symptomatic or asymptomatic. There was increase of performed work during exercise tests after both treatment periods. The efficacy of Isoket 120 mg and Adalat Retard 2 x 20 mg daily in the treatment of patients with active variant angina pectoris was comparable in our study. 3 patients suffered untolerable headache during isosorbide dinitrate phase and had to terminate treatment after first day only.