TNF, IL-1, IFN-gamma and PGE2 secretion of peritoneal macrophage obtained by peritoneal washing at the first day after laparotomy from 19 patients with cervical cancer and 19 with ovarian cancer, who were treated with sizofiran (SPG) intramuscularly before laparotomy or with recombinant interferon gamma (rIFN) intraperitoneally at the day of laparotomy, were studied. Treatment with SPG and rIFN significantly increased the number and secretion of TNF, IL-1 and IFN-gamma (p less than 0.05) but not that of PGE2. A high correlation between secretion of TNF and IFN-gamma (r = 0.99, p less than 0.01) was observed. These data suggest that potent tumoricidal activity of peritoneal macrophage obtained from the patients with gynecological malignancies could be expected by the treatment with SPG and rIFN due to the increased secretion of TNF, IFN-gamma and IL-1 and inhibition of increased secretion of PGE2.