We report a case of advanced gastric cancer with Virchow's node metastasis which responded to concomitant plasma exchange and immunochemotherapy. Plasma exchange was conducted three times in total (once a week) using a membrane type plasma separator, with fresh frozen plasma as exchange fluid. Immunochemotherapy was performed simultaneously using MMC, FT and OK-432. By the end of the third plasma exchange, Virchow's node was confirmed by palpation and ultrasonic examination to have vanished. Diminution of the gastric cancer, and improvement of stenosis of the stomach were confirmed under endoscopy. We surmised that plasma exchange eliminated the immunosuppressive substances in serum, and intensified the anticancer effects of MMC and FT, resulting in the disappearance of the Virchow's node and diminution of the gastric cancer itself.