Pulsed doppler echocardiography is reported to be a reliable method for evaluating pulmonary hemodynamics in patients with cardiovascular diseases, but not with chronic obstructive pulmonary disease (COPD) because of the difficulty in obtaining an appropriate echo-window in such patients. We examined 23 patients with COPD by doppler echocardiography (Hewlett-Packard, HP77020CV) with a 2.5 MHz transducer via the subcostal approach in a supine position. The right side of the heart catheterization was performed simultaneously in sixteen of these patients. The remaining 7 patients received the same procedure within one week of the doppler echocardiography. Adequate ejection flow pattern from the right ventricle was obtained in all the patients. Significant negative linear relationships were found between pulmonary arterial pressure and acceleration time (r = -0.67) and ejection time (r = -0.52). These findings show that doppler echocardiography can be useful when evaluating pulmonary hemodynamics even in patients with COPD.