To determine whether interstitial pulmonary edema occurs or not in experimental cirrhotic rats, male Sprague-Dawley rats were given carbon tetrachloride subcutaneously in order to induce liver cirrhosis. The percent lung water content of the cirrhotic rats increased to 79.1 +/- 0.7% compared to 77.4 +/- 0.9% in control rats (p less than 0.001). Microscopically, 8 of 10 cirrhotic rats show the pulmonary interstitial thickening with lymphocytic infiltration. Moreover, perivascular edema with dilatation of lymphatics was frequently recognized. This suggested that fluid retention of pulmonary interstitial tissue would occur in the cirrhotic rats, and then perivascular edema would compress the small airways of the lung in cirrhotic rats.