A localized pulmonary infarction was produced by injecting a starch suspension into the pulmonary artery wedge position of one lung lobe in pentobarbitalized dogs, and the effect of bilateral surgical removal of the sympathetic chain was determined. Edema is significantly inhibited in ipsilateral and contralateral lung lobes of sympathectomized dogs. It is concluded that the sympathetic nervous system plays a major role as an efferent path in reflex production of pulmonary edema by starch emboli in the dog. There is, incidentally, evidence that sympathectomy lowers the pressure gradient between the pulmonary artery and pulmonary arterial wedge position in the dog.