We report the case of a 65-year-old woman with no history of respiratory disease who suffered onset of dyspnea after an episode of pseudoinfluenza. Dyspnea progressed such that within 15 days it was triggered by minimal effort. The patient died 15 hours after admission to our hospital, with a clinical picture of adult respiratory distress. Autopsy allowed us to rule out several diseases and arrive at a diagnosis of acute interstitial pneumonia, consistent with clinical course, anatomical and pathological findings as described in the literature.