Adult respiratory distress syndrome (ARDS) notably produces bilateral homogeneous alveolar infiltrates and decreased lung compliance. We encountered a patient whose severe underlying emphysema altered these distinctive clinical features. The chest roentgenogram showed bilateral infiltrates containing multiple radiolucencies that simulated a cavitary process. Also, lung-chest wall compliances measured during mechanical ventilation were higher than usually observed in patients with ARDS. We suggest that the pathologic features of the emphysematous lung with multiple blebs and decreased elastic recoil properties impart these unique findings. When ARDS develops in a patient with severe underlying emphysema, an atypical presentation may produce a confusing clinical picture.