A 39-year-old man developed massive bronchorrhea (2 to 3.5 L/d) with electrolyte and volume depletion about 2 years after undergoing a Whipple's procedure for pancreatic carcinoma. An open lung wedge biopsy specimen was consistent with metastatic adenocarcinoma with extensive growth along preexisting pulmonary architecture. Chemical analysis of the bronchial fluid revealed markedly elevated levels of amylase confirming the pancreatic origin of the tumor. The mechanism of massive bronchorrhea is not known. Chemical analysis of bronchial fluid in comparison to serum and the temporary response to chemotherapy are most consistent with secretory and transudative mechanisms.