For bronchoalveolar lavages (BAL) after lung transplantation in the rat two different tubes for creation of a permanent tracheostoma were devised and tested. Typ I was of plastic material and required closure of the trachea oral of the tube thus excluding the upper respiratory tract for breathing. All these animals deprived of their sense of smell and direction died within 50 hours despite optimal husbandry. Typ II was a T-shaped metall tube allowing normal nasal breathing. This tube was well tolerated by the animals and facilitated repeated BAL. BAL on day 3 following tracheotomy with 5% lymphocytes, 2% polymorphonuclear leukocytes and 95% alveolar macrophages was considered to be normal when compared with human findings. An increase in polymorphonuclear leucocytes and epithelial cells together with bacteria on day 6 was believed to be due to tracheobronchitis. This assumption was supported by the fact, that both cell types and the number of bacteria significantly decreased 3 days later. A steady increase of lymphocytes seems to be associated with repeated BAL.