Purpose : This study evaluated early and late pulmonary hypertension ( PH) in preterm infants and assessed the relation of PH and bronchopulmonary dysplasia (BPD). Methods : Sixty-seven preterm infants 30 weeks’ gestation underwent echocardiography within 14 days after birth for early PH and over 28 days after birth for late PH. We measured tricuspid regurgitation (TR) peak velocity, pulse Doppler–derived myocardial performance index of right ventricle (RV MPI), eccentricity index (EI), and tricuspid annular plane systolic excursion (TAPSE). Results : The median gestation age of patients was 27 weeks (range, 23–30 weeks) and median birth weight was 1,030 grams (range, 450–1,780 grams). TR jet was only found in 19 patients (28.4%). Patients with symptomatic early PH (n=11) showed a significantly lower systolic EI and a significantly higher incidence of RV MPI ＞ 0.38 and TAPSE 0.5cm than patients without PH. The incidence of symptomatic early PH was highest in severe BPD, although this was not statistically significant. Early echocardiographic parameters are not associated with BPD development. Patients with severe BPD showed a significantly higher RV MPI and a significantly higher incidence of RV MPI ＞ 0.38 than patients with mild BPD, and a significantly lower systolic EI and a significantly higher incidence of systolic EI 0.81 than patients without BPD. Conclusions : Systolic EI, RV MPI, and TAPSE were well correlated with symptomatic early PH, while systolic EI and RV MPI could be useful predictors of late PH in preterm infants with BPD, even if they did not present PH symptoms.