Pleural effusions occur in up to 40% of patients with acute pancreatitis and occur almost unilaterally on the left. However, rarely bilateral or right-sided effusions have been reported. This predilection o effusions for the left pleural cavity may be largely explicable on simple anatomical ground, since the pancreas is more intimately related to the left hemidiaphragm than to the right. The mechanism o acute pleural effusions associated with acute pancreatitis can be explained by chemical irritation o the diaphragmatic lymphatics. Enzyme-rich fluid below the diaphragm originated from the inflammed pancreas is transported through the dilated lymphatics into the chest. Therefore, right-sided pleural effusion can occur by aberrant lymphatic transfer to the right pleural cavity. We experienced a case of acute pancreatitis with right-sided pleural effusion and thus, discuss the pathogenesis of this case with review of literatures.