Objective To assess the value of prenatal ultrasonography in diagnosing fetal absent pulmonary valve syndrome(APVS). Methods This was a retrospective study of 8 fetuses with absent pulmonary valve syndrome. Fetal echocardiography and segmental analysis were used to determine the atrial situs,atrioventricular connections and ventriculoarterial relationships. Cardiac chamber dimensions,Doppler studies of the atrioventricular valve and semilunar value were recorded, and cardiothoracic ratio were calculated. Results Levocardia,normal situs and atrioventricular connections were present in all cases. All cases showed typical signs:severe dilatation of the pulmonary trunk and it's branches, and concurrent occurrence of pulmonary valve stenosis and regurgitation. In 6/8 there was an associated ventricular septal defect,overriding aorta and absent arterial duct(Fallot-like APVS),while in 2/8 there was an assoiciated intact ventricular septal and patent arterial duct. Extracardiac malformations were detected in 5 cases.Conclusions APVS can be accurately diagnosed by prenatal ultrasonography but we should pay more attention to the ventricular septal and arterial duct,due to the existence of two variants.