The effect of cell suspension of Propionibacterium granulosum strain KP-45 injected intratumorally was estimated in patients with advanced malignant neoplastic disease of the upper and lower part of the digestive tract. These patients received no other anticancer treatment, and results of therapy with P. granulosum were compared with a control group of nontreated patients. In the course of immunotherapy, general clinical state, dynamics of tumor growth as judged by endoscopy and morphologic, biochemical and immunologic parameters of the peripheral blood, were evaluated. Treatment with KP-45 preparation usually resulted in partial regression of tumor growth, accompanied by improvement of the clinical state of these patients, as well as reappearance of normal values of blood picture and biochemical parameters. Enhancement of cellular immune response, evaluated by increased number of peripheral blood T lymphocytes and increased skin reactivity to PHA and PPD, was observed. No serious side effects or complications of local immunotherapy were noted. No patients who had immunotherapy suffered from bacterial infection; this was not the case in the control group.