We evaluated the accuracy of a noninvasive method for estimating right ventricular systolic pressures in patients with tricuspid regurgitation detected by Doppler ultrasound. Of 62 patients with clinical signs of elevated right-sided pressures, 54 (87%) had jets of tricuspid regurgitation clearly recorded by continuous-wave Doppler ultrasound. By use of the maximum velocity (V) of the regurgitant jet, the systolic pressure gradient (delta P) between right ventricle and right atrium was calculated by the modified Bernoulli equation (delta P = 4V2). Adding the transtricuspid gradient to the mean right atrial pressure (estimated clinically from the jugular veins) gave predictions of right ventricular systolic pressure that correlated well with catheterization values (r = .93, SEE = 8 mm Hg). The tricuspid gradient method provides an accurate and widely applicable method for noninvasive estimation of elevated right ventricular systolic pressures.