Pleural effusion due to hepatic cirrhosis with ascites is well known, although hepatic hydrothorax in the absence of ascites is a rare condition, the pathogenesis of which is still unknown. We report a case of hepatic hydrothorax without ascites confirmed by the intraperitoneal injection of Tc-99m macroaggregated serum albumin (Tc-99m MAA) that demonstrated the passage of Tc-99m MAA into the right pleural cavity.