The combination treatment of non-specific immunomodulator Lentinan (LNT) and OK-432 is effective for controlling Th1/Th2 balance and inducing Th1 dominant status in cancer patients. According to this rationale, we tried an administration of LNT and OK-432 in the pleural or peritoneal cavity for patients with malignant effusion. In all 21 lesions of the 20 cases, 10 revealed a complete disappearance and 7 revealed diminution of the effusion. The efficacy of this treatment is 81%. All patients developed a clinical efficacy in 1 to 3 courses of this treatment, and 9 lesions developed clinical efficacy in only 1 course. None of patients developed toxic symptoms LNT, and 10 developed a low grade fever by OK-432. The combination of LNT and OK-432 is effective and for QOL conserving loco-regional treatment.