To evaluate intraperitoneal distribution of drug after surgery, a radiographic study using peritoneography was performed. Five cases with positive intraoperative cytology of gastric carcinoma were studied. The tip of the subcutaneous injection catheter was located in the Douglas's fossa intraoperatively. As control group, 7 cases of inguinal hernia who underwent radical resection for gastrointestinal carcinoma and 2 cases who failed intraperitoneal chemotherapy through injection port, underwent peritoneography. The distribution of contrast medium in the peritoneal cavity was compared between groups. (Conclusion) The distribution of drug after gastric surgery was observed in all of the peritoneal cavity below the transverse colon. Distribution was not observed in the region where lymphadenectomy or bursectomy was done. The peritoneum has an important role in the distribution of drugs in the peritoneal cavity.