Polysplenia syndrome is a rare congenital anomaly frequently associated with various visceral anomalies. The most frequent manifestations of this syndrome, in addition to polysplenia are malrotation, congenital heart diseases and gastrointestinal, genitourinary and vascular abnormalities. In this report, we present an adult case of ascites due to prehepatic portal hypertension associated with portal cavernous transformation. The patient had a left-sided liver, right-sided multiple splenules and stomach, interrupted inferior vena cava with azygos continuation and extensive ascites. The portal vein was not observed and collateral vascular structures of cavernous transformation were identified in the hepatic hilus. Portal cavernous transformation with various congenital abnormalities has been reported in the literature; however, there are no cases of polysplenia syndrome presenting with ascites associated with portal cavernous transformation.