The antianginal effects of oral isosorbide 5-mononitrate(Elantan(R)) were evaluated in 14 patients with angina pectoris by repeated treadmill exercise test before and after oral Elatan(R) therapy(49 mg/day for 14 days) in Chungnam National University Hospital from Dec., 1988 to Jun., 1989. The results were as follows; 1) The patients were 45 to 71 years old(mean 57) and consisted of 9 men and 5 women. 2) There were no significant effects on resting hemodynamic data such as heart rate, systolic and diastolic blood pressure after Elatan(R) therapy. 3) Peak heart rate, peak blood pressure and peak heart rate-systolic blood pressure product(double prduct) during exercise showed no changes. 4) Exercise durations were prolonged in 11(79%) patients, did not changed in 2(14%), and shorted in 1(7%) patient after therapy(399+/-189 seconds vs 529+/-230, second P<0.01). 5) Three patients complained of headache, but none discontinued medication.