Complete trisomy 9 is a very rare chromosome aneuploidy, associated with specific patterns of multisystem dysmorphism and a wide spectrum of congenital anomalies. We present a case of complete trisomy 9 with prenatal sonographic findings in the second trimester. The combination of sonography and karyotyping from cordocentesis enabled us to establish the prenatal diagnosis. An additional clinical feature of this syndrome that has not been reported previously is an aortopulmonary communication. A review of the literature specifically dealing with prenatal sonographic findings with complete trisomy 9 is also presented.