A 22-yr-old man developed severe pulmonary edema after blowing air into tubing connected to a catheter inserted in a vein in his forearm. Pulmonary edema was rapid in onset, peaking in intensity about 12 h after the air had been insufflated. The patient's edema fluid to plasma protein concentration ratio of 0.79 showed that the edema fluid was rich in protein. Vascular pressures were normal except for mild pulmonary arterial hypertension and systemic hypotension. The patient's clinical course, edema fluid protein concentration, and vascular pressures were characteristic of an increased microvascular permeability type of pulmonary edema. The patient recovered fully within 48 h of the air infusion. His response to venous air embolism was similar to findings in an experimental model of pulmonary edema in sheep infused with venous air emboli. As long as air is not infused continuously for long periods or in very large amounts, this disorder is probably self-limiting, and supportive care may be the only treatment necessary.