In the recent years the essential role of granulocytes in the initiation and amplification of the pathomechanisms resulting in the adult respiratory distress syndrome (ARDS) has been documented [3, 5-7]. On the contrary, there is only little information about the participation of alveolar macrophages in the ARDS pathogenesis [4] and no report on alterations of macrophage functions during the development of the ARDS.