Background: Nitroglycerin (NTG) is used as a physiological tool to assess arterial baroreceptor reflex sensitivity in humans. We investigated the change of short-term heart rate (HR), systolic blood pressures (SBP) and diastolic blood pressure (DBP) after nitroglycerin. Pulse wave velocity (PWV) is widely used as noninvasive modalities for evaluating atherosclerosis. Therefore, the present study was designed to investigate the difference in HR, SBP and DBP by repeated measures method after NTG in patients with chest pain. Methods and Results: A total of 73 patients with chest pain were divided into two groups according to coronary angiogram (CAG) finding. Eight-minute recordings of HR and blood pressure were performed during 0.6 mg NTG administration in 45 patients (Group I: 55.02짹10.9years, 30 males) with normal CAG and 28 patients (Group II: 56.07짹10.8years, 25 males) with angiographically diagnosed coronary heart disease. There were no significant differences in baseline clinical characteristics and biochemical markers between two groups. The hcPWV was significantly increased in Group II than in Group I (949.5짹170.9 cm/s vs. 1197.1짹279.2cm/s, p = 0.010) and the hfPWV was significantly increased in Group II than in Group I (1440.3짹 214.8 cm/s vs. 1362.7 짹 404.5 cm/s, p = 0.017). DSP was significantly different between two groups (Tab 1). Conclusion These results indicated that elevated carotid and aortic stiffness and difference in DBP by NTG in chest pain are related to structural change in coronary arterial wall.