The preoperative preparation program based upon the experience of treating 465 patients with acute pyonecrotizing diseases of lungs was developed. This system takes into account the stage of the disease (I--septic, II--stabilization, III--remission), endotoxicosis intensity and non respiratory activity of the affected lung (NRAL). The patients of the first group (I stage of the disease) with long-term subclavian vein catheterization were on the special scheme of NRAL correction, their supurative focuses being treated with electrized hypochlorite sodium solution. The system appeared to be effective in managing patients, in the first group--254 patients of which 202 (79,9%) were successfully treated without operation, as for the second group, there were only 52 (40,6%), in the third--26 (31,3%). By limiting and stabilizing the process, the effect of this preoperative preparation program was also seen in other patients. It allowed to perform less traumatic operations (lung resection) in 109 patients of the 179 operated on, with 8,7% of postoperative complications in 8,7% in the first group vers. 18,4% and 24,6% in the second and third, respectively. Thus the above mentioned results show the proposed system to be effective.