Clinical, immunological and bacteriological studies were carried out in 63 children with the so-called staphylococcus destruction of the lungs. It was shown that in some of the cases destructive process in the lungs, along with the pathogenic staphylococcus, could be caused by the Gram negative bacteria (Proteus, Bac. pyocyaneus, etc.). It was found that in children of different age groups the titre of antistaphylococcus antibodies up to 0.5 AU/ml was normal and pointed to the absence of any inflammatory disease of staphylococcus etiology; a titre of 2 AU/ml - and overcould be considered as diagnostic. In connection with bacterial poly-etiology of acute destruction of the lungs in children it is suggested that it should be designated as "acute purulent destructive pneumonia". The importance of immuno-bacteriological studies in children with diseases with the mentioned pathology is emphasized; these examinations permit to choose proper complex therapy.