Bearing in mind the complexity of the topic and its variability owing to the progress made in antibiotic management, and the development of many concepts concerning the pathogenesis and biochemistry of major burns, the already massive literature is supplemented by the addition of relatively recent data to enable comparisons to be made with regard to the quality and frequency of isolation of the bacterial flora observed in such patients, and above all their sensitivity to currently employed antibiotics. The investigation was conducted on patients admitted to the Turin CTO Major Burns Centre between 1972 and 1977. Initially (1972-1975), a microbiological examination was made of purulent secretions from wounds. Subsequently, management was prevalently directed to the early excision of injured surfaces, and attention was therefore directed to the indwelling venous catheters used in treatment and parenteral alimentation. In cases examined in parallel, moreover, there was often a substantial similarity between wound and catheter flora, and when only one species was present in the wounds, the catheter was often sterile. Furthermore, numerous data were collected from antibiograms relating to the most frequently encountered micro-organisms. These usually displayed wide resistance spectra, especially with respect to the most commonly used of historically oldest antibiotics, whereas their resistance to those recently introduced was generally lower. The question of provenance (from the patient himself, the hospital or its medical and paramedical staff) is also examined. Reference is made to a point that has recently become important in the treatment of burns, namely the ascertainment of the degree of contamination not only on the surface, but also in the immediate sub-surface of the lesions, so as to permit a suitable excision of the eschar and skin transplantation. When a sufficient number of findings exist to support this new concept, it will certainly give rise to further studies and research aimed at bringing new, important data to this so rich and multiform topic.