We examined the effects of intravenous infusion of 5-FU and intraperitoneal injection of low-dose CDDP on 3 cases with ascites owing to peritonitis carcinomatosa of postoperative gastric carcinoma and debility. Intravenous infusion of 5-FU (250-1,000 mg/body) and intraperitoneal injection of CDDP (20-25 mg/body) carried out for 2-5 days. As a result, QOL of 3 cases was fairly improved. The PS (Performance Status) of 2 cases improved from Grade 4 to 2, and another one improved from Grade 4 to 3. Adverse effects of Grade 1 according to the WHO criteria were observed in 1 case (leukocytopenia and diarrhea). This palliative chemotherapy method appeared to be safe and effective for ascites due to peritonitis carcinomatosa of postoperative gastric carcinoma and debility.