Background The efficacy and safety of nicorandil were evaluated in Chinese patients with stable angina pectoris (AP) in a double-blind, multicenter, active-controlled, randomized clinical trial. Methods and Results After a 2-week washout period, 232 patients with stable AP were randomized to receive either nicorandil (5 mg tid; 115 patients) or isosorbide mononitrate (ISMN: 20 mg bid; 117 patients) for 2 weeks. Exercise capacity, number of weekly anginal attacks, nitroglycerin (NTG) consumption, and safety were evaluated. Nicorandil and ISMN significantly prolonged the time to I mm ST-segment depression in an exercise tolerance test. Both drugs improved the total exercise time and the time to onset of chest pain. There was no significant difference between the 2 groups. Nicorandil significantly decreased the number of anginal attacks and NTG consumption. ISMN decreased the number of anginal attacks significantly; however, there was no significance in NTG consumption, and the ratio of anginal attack reduction was at least 50% was significantly higher with nicorandil. Nicorandil was well tolerated and there was no safety profile difference compared with ISMN. Thus, nicorandil may have equivalent or better antianginal effect than ISMN. Conclusions Nicorandil is beneficial as treatment for AP.