During a 3-year period (1984 through 1987), 40 patients with smoke inhalation, cutaneous burns, or a combination of both injuries were studied. Injuries were assigned to the three categories on the basis of bronchoscopic findings and clinical history. Eleven patients had simultaneously sustained a common smoke-inhalation injury without burns while trapped in a burning ship; twelve patients had massive cutaneous burns over 50% of the total body surface area (TBSA); and seventeen patients had cutaneous burns over more than 30% of the TBSA and inhalation injury. Colloid oncotic pressure was maintained with salt-poor albumin infusion. Central venous pressure, arterial saturation, inspired oxygen, arterial pressure, and urine output were continuously monitored. Extravascular lung water (EVLW) and cardiac output were measured by the double indicator (thermal dye dilution) technique. EVLW remained normal throughout the study period in the group of patients with burns alone. In the first 24 hours after injury, EVLW increased in both groups with smoke injury and remained elevated for more than 48 hours after injury in patients with smoke injury only. The group with both smoke-inhalation and burn injuries showed an early increase in EVLW, which returned to normal by 28 hours after injury and which remained normal until 5 days after injury. The EVLW level then increased again until the end of the study period. In this study, lung edema formation is attributed to the toxic effect of smoke inhalation.