Carbohydrate antigen 19-9 (CA19-9) is a specific tumor marker of the biliary, pancreatic and gastrointestinal tracts. CA19-9 is occasionally elevated in serum in patiens with benign pulmonary diseases such as bronchiectasis, idiopathic interstitial pneumonia or collagen disease-associated pulmonary fibrosis. Intralobar pulmonary sequestration is an uncommon congenital lung anomaly. It is dissociated from the normal tracheobronchial tree and is supplied by an anomalous systemic artery. There have been some reports of elevation of CA19-9 in this lesion. We report a case of intralobar pulmonary sequestration with elevated serum CA19-9 in a 29-year-old man who was diagnosed with bronchiectasia of left lower lung field on general check up. He had no evidence of any malignant disease in pancreatobiliary or gastrointestinal tracts. Elevated serum CA19-9 level might be encountered with benign pulmonary disease such as pulmonary sequestration.