To determine the feasibility of the non-invasive determination of systolic pressure of the pulmonary artery and the right ventricle in pediatric patients, the velocity of tricuspid regurgitation was measured in 30 patients using a contrast enhanced Doppler echocardiography. After sonicated albumin injection, trivial tricuspid regurgitation signals were enhanced in 27 patients (90%). Peak systolic velocity was not altered by before and after sonicated albumin injection in 2 patients. Right ventricular (RV) systolic pressure obtained by continuous wave Doppler during sonicated albumin enhancement corresponded very closely to that measured by catheter in 27 patients (r=0.96). In 27 patients, difference of estimation of RV systolic pressure by non-enhanced Doppler and enhanced Doppler with sonicated albumin was statistically significant (32.3±27.6mmHg versus 2.9±7.7mmHg p<0.001). Systolic pressure of pulmonary artery was estimated by RV systolic pressure measurement (by enhanced Doppler method) minus peak pressure gradient across the pulmonary valve (non-enhanced Doppler method). Pulmonary arterial systolic pressure measured by enhanced Doppler method and that by catheter method were highly significant (sonicated albumin method, r=0.95). This technique may be a valuable non-invasive method for determining an accurate right ventricular and pulmonary arterial systolic pressures in this setting.