COMPARED with other fields of burn therapy, thermal respiratory injuries still pose a formidable problem with a high rate of mortality. How urgent this problem really is becomes evident when considering the incidence of such injuries during the recent war actions in Indo-China, in the Near East and in Cyprus. The crews of armoured vehicles, of aircraft and in ships are the preferential victims. Taking civilian accidents into account as well, such as industrial explosions, traffic accidents and big fires this problem reaches serious proportions. From a pathophysiological point of view the evaluations given by Dressler and Skornik (1971), by Song et al. (1971) and by Ohura et al. (1971) are still valid. The analysis of Ginzburg (1971) applies even more so to inhalation burns. The purpose of this study was to evaluate possibilities of dealing with the oedema that develops very soon after the inhalation of hot air or steam. It is the first stage in the ensuing process which leads to respiratory insufficiency, cellular damage, and sepsis often enough to death. The scale of injury ranges from superficial burns of the respiratory tract and oedema to extensive damage of the alveolar walls, the bronchial epithelia and the oro-pharyngeal tract. The therapeutics of choice would appear to be the whole range of corticosteroids. Schmiedek et al. (1972) and Reulen et al. (1972) showed in the case of traumatic and inflammatory brain oedema that these drugs not only reduce the oedema but normalized the cellular metabolism at the same time, the intraas well as extracellular electrolytes and cellular membrane function. Dressler and Skornik examined the question of corticosteroids in burns very thoroughly. They showed that dexamethasone by systemic applicationraised the mortality of scaldedanimals from 5 to 64 per cent. In animals seeded with Pseudomonas the mortality rose to over 96 per cent in spite of antibacterial treatment. Trying to find a way out of this dilemma, that is, on the one hand the need for corticosteroids and their anti-inflammatory and anti-oedematous effect, and on the other the apparent total and fatal breakdown of the resistance against infection as a result of systemic application of the same corticosteroids, two possibilities offered themselves for study, the local use of glucocorticoids and the aldosterone antagonist, spironolactone.