The authors executed a prospective clinic study evaluating, whether at the admittance or after surgery, the immunity status of 30 patients with a thoracic neoplasm, admitted to Department of Thoracic Surgery, I School of Medicine, Naples. Only 21 of them, immunodepressed at the admittance, were accepted to trial and assigned respectively to A Group destined to surgery (10 patients) and to B check Group (11 patients). In the A Group the effectiveness of the immunotherapy was valued in the prophylaxis and in the postoperative septic complications' therapy. The global incidence of those complications was of 6 cases, of which 10% only in A Group and 45% in B Group. In the operated patients the septic complications had few repercussions on general status and were rapidly and totally dominated in strict correlation with an adequate immunoreconstitution.