A 75-year-old man was admitted to the hospital due to acute onset of a dry cough and dyspnea on exertion. Arterial blood gas analysis showed hypoxemia (PaO2 = 63 Torr) on room air. Chest radiography and computed tomography showed diffuse bilateral infiltrates. Adult respiratory distress syndrome was diagnosed from the findings described above and from the lack of evidence of left heart failure. Diffuse alveolar damage was confirmed at autopsy. During the course of his illness, the patient underwent bronchoalveolar lavage five times. The recovered fluid had high concentrations of interleukin-8 (IL-8), with a maximum of 6260 pg/ml and a minimum of 190 pg/ml, and these values correlated with the number of polymorphonuclear cells in the fluid. Levels of leukotriene B4, another chemotactic factor for PMN, in the lavage fluid were not high. We conclude that IL-8 was a major chemoattractant for PMN in the alveoli of this patient.