In two patients a documented Texas A2 influenza infection was associated with the development of interstitial pulmonary disease. One patient had an acute fulminating process resulting in respiratory failure and necessitating ventilatory assistance. Open lung biopsy revealed a histologic picture consistent with usual interstitial pneumonia (UIP). The other patient had a subacute course, and the pulmonary histology showed UIP with features of desquamative interstitial pneumonia. The influenza virus may have had an etiologic role in the development of the interstitial lung disease in our two patients.