Patients with esophageal cancer are susceptible to other primary cancers, but multiple primary cancers involving the esophagus and jejunum are rare. We herein report a case of primary jejunal cancer as a component of metachronous triple primary cancers including esophageal cancer and ascending colon cancer. A 63-year-old male patient with a history of surgery for esophageal cancer and ascending colon cancer was admitted to our hospital after experiencing 1 month of repeated vomiting and epigastric abdominal pain. Esophagogastroduodenoscopy, duodenography, and computed tomography revealed a jejunal tumor located 2 cm from the ligament of Treitz on the anal side. Partial resection of the jejunum with lymph node dissection was performed. The postoperative course was uneventful, and the patient remains well with no signs of recurrence 10 months after the operation. This is the first report of curative resection of triple primary cancers of the esophagus, jejunum, and colon. Patients with a history of esophageal cancer are susceptible to other primary cancers, and it is important to perform surveillance for the subsequent development of other cancers.