Background and Objectives : Nicorandil has the pharmacologic effects similar to currently-taken nitrate and in respect to the K-channel opening action in vascular smooth muscle cells, and the frequency of use is being increased. This study was designed to compare the effect of nicorandil with nitrates as early therapeutic agent for acute non-ST segment elevation myocardial infarction (NSTEMD. Subjects and Methods : A total of 67 patients (34 nicorandil group, 33 nitrates group) who had acute NSTEMI on admission into emergency room were enrolled and randomized in this study. All patients in both group underwent coronary angiography / percutaneous coronary intervention during hospitalization, and follow-up after discharge was performed at OPD on 1st, 3rd, & 6th months. The frequency of major adverse cardiac event (MACE) and significant adverse effect of used agents was investigated. Results : There was no demonstrable difference of clinical profile between both group. The result of comparative analysis revealed slight decrease of reinfarction rate in nicorandil group without statistical significance(2.9% versus 9.1%, p value = 0.076), and no meaningful difference on aspect of target vessel revascularization and cardiac-origin death. No ominous distinction of frequency of the adverse drug effect was noted in both group. Conclusion : In spite of statistical insignificance, the early use of nicorandil for acute NSTEMI may reduce in-hospital reinfarction incidence. The other profile showed no notable advantage compared with nitrates.