We report 42 cases of gastric cancer with peritoneal carcinosis treated with intraperitoneal chemohyperthermia. Intraperitoneal chemohyperthermia was achieved with a closed sterile circuit containing mitomycin C, 10 mg/l producing an input temperature varying from 46 to 49 degrees C for 90 minutes. There were three postoperative deaths: one pulmonary embolism at day 4, one multiple organ failure et day 4, and one septic shock at day 25 due to a colonic fistula. Two patients suffered complications: one opening of the duodenal stump requiring reoperation on day 5, and one prolonged postoperative ileus lasting to day 10. Of the 12 patients with ascites, resorption was achieved in 8. In patients with early-stage peritoneal carcinosis (granulations less than 5 mm) survival at 1, 2 and 3 years was 90%, 61% and 41% respectively. For those with more extensive carcinosis, survival at 1 year was 10%. Five patients survived more than 30 months, three have survived to 34, 43 and 73 months. Intraperitoneal chemohyperthermia is a new treatment for carcinosis of gastric origin. These early results must be assessed further with larger controlled.