Extravascular lung water was assessed using a double-indicator dilution technique (thermal-green dye) in 15 men who had radiographic and clinical evidence of cardiogenic interstitial and alveolar pulmonary edema. Eight patients had suffered an acute myocardial infarction and seven had a history of chronic congestive cardiomyopathy and worsening of previous clinical signs and symptoms. At the same level of pulmonary capillary wedge pressure and similar arterial oxygen tensions extravascular lung water was significantly greater in the group with chronic congestive cardiomyopathy (p less than .05). The two groups did not differ with respect to systemic arterial pressure, resistance, or cardiac index.