Pulmonary valve echogram and right cardiac catheterization were simultaneously performed in 18 patients suffering from heart disease in whom pulmonary hypertension was suspected. Echocardiography was employed to measure right preejection period (RPEP), right ventricular ejection time (RVET) and RPEP/RVET ratio. Cardiac catheterization was used to determine pulmonary artery diastolic pressure (PADP), pulmonary artery systolic pressure (PASP), pulmonary artery mean pressure (PAMP) and right ventricular and diastolic pressure (RVDP). Each of these pressures was compared to each of the echo-date by means of regression analysis. The best correlation (r = 0.970; p less than 0.0005) was between PADP and RPEP/RVET ratio. We also found that RPEP/RVET ratio and RVET were each good predictors for the pulmonary artery pressures.