This is a report on a case of CA19-9-producing cancer of esophagogastric junction with rectal cancer and a suspicion of Krukenberg tumor, a metastasized ovarian tumor that would mean an inoperable condition of cancer progression if that were true. This was a case of a woman in her 60s who was diagnosed with double cancers at the esophagogastric junction and rectum with a swollen left ovary. She had a laparoscopic bilateral salpingo-oophorectomy to get a histologic diagnosis, which should affect the subsequent therapeutic strategy because metastasis to the ovary meant an inoperable cancer progression. The resected ovary was diagnosed as juvenile granulosa cell tumor, but not Krukenberg tumor. Thus, subsequent curative surgeries, such as thoracolaparotomy for esophagogastric junction cancer and robot-assisted surgery for rectal cancer, were performed. Immunohistochemical examination revealed that the expression of CA19-9 was strongly observed in the tumor of esophagogastric junction, but not in the tumors of rectum or ovary. Furthermore, serum CA19-9 was drastically decreased after the resection of esophagogastric junction cancer. In aggregate, this esophagogastric junction cancer met the criteria of CA19-9-producing gastric cancer defined by Okinaga et al. So far, 46 cases of CA19-9-producing gastric cancer including this case have been reported in Japanese literature. Interestingly, this case had another characteristic of juvenile granulosa cell tumor, one of borderline malignant sex cord-stromal tumors rarely found in adults.