Surface tension and the biochemical composition of lung washings were studied in rats 24 h after bilateral cervical vagotomy. A significant decrease in body weight, rate of breathing, stability and hysteresis shape indexes and hysteresis loop areas were noted. The gamma max, gamma min, gamma stat, indexes of compressibility, the number of cells and the protein content of washings were significantly increased. There were only minor changes in the absolute amount of phospholipids but their relative rate was significantly lower. Interstitial lung edema and early bronchopneumonia were confirmed histologically.