It is very important to control the Th2-dominant condition in cancer patients while they are undergoing immunotherapy. OK-432 powerfully guides Th1 cytokine, but sometimes it can not eliminate the Th2 dominant state in cancer patients, which is needed to induce Th2 cytokine. Premedication with combined LTN and OK-432 is an effective therapy for controlling the Th1/Th2 balance. We tried administering LTN and OK-432 in the pleural or peritoneal cavity for patients with malignant effusion. Of all 9 lesions of the 8 cases, 6 showed complete remission and 1 showed partial response. The level of IL-12 (p70) and IFN-gamma in the pleural effusion or ascites of the combination group was higher than the OK-432 only group. In conclusion, LTN and OK-432 combined therapy appears to be an effective local treatment.