To evaluate prenatal echocardiography predictors of postnatal pulmonary stenosis (PS) requiring infant surgery. Consecutive fetuses with suspected cardiac anomalies (n = 303) were screened. After excluding cases of induced abortion (n = 18), the remaining cohort of 285 fetuses was analyzed. Postnatal follow-up confirmed PS in 30 neonates. Diagnostic consistency (kappa statistics) and risk factors (logistic regression/ROC analysis) for surgical intervention were assessed. This study enrolled fetuses with structurally abnormal hearts prenatally diagnosed with PS, defined by accelerated pulmonary forward flow (peak velocity > 1 m/s) concomitant with pulmonary valve abnormalities (thickening/increased echogenicity/restricted opening) or main pulmonary artery narrowing with post-stenotic dilation. Exclusions: ① PS with complex congenital heart disease (e.g., tetralogy of Fallot, ventricular septal defect, pulmonary atresia, transposition of great arteries); ② lost-to-follow-up/incomplete data; and ③ pregnancy terminations. The mean gestational age was 28.5 ± 4.91 weeks in the non-intervention group and 27.6 ± 3.13 weeks in the intervention group. Moderate prenatal–postnatal diagnostic agreement was observed (kappa = 0.609, P < 0.001). Key surgical predictors included severe tricuspid regurgitation (OR = 14.167), pulmonary valve abnormalities (OR = 11.250), elevated flow velocity (≥ 1.85 m/s; OR = 3.939), and reduced PA/Ao ratio (≤ 1.415; OR = 0.005, all P < 0.05). Combined indicators demonstrated high predictive accuracy (AUC = 0.934). Pulmonary valve abnormalities showed 94.7% sensitivity; flow velocity ≥ 1.85 m/s yielded 73.7% sensitivity and 91.3% specificity. Prenatal echocardiography effectively stratifies PS severity and surgical needs. Critical markers (valve anomalies, flow velocity ≥ 1.85 m/s, PA/Ao ≤ 1.415, severe regurgitation) optimize risk prediction, guiding clinical management.