Gastroduodenal ulcers in renal transplant recipients are usually originated from excessive acid secretion or infection of Helicobacter pyroli. Herein, we report a case of cytomegalovirus (CMV)--induced gastric ulcer following cadaveric renal transplantation. The patient was a 48-year-old man with chronic renal failure and received cadaveric renal transplantation. A month later, he had epigastralgia without CMV-positive antigenemia and received gastrointestinal fiberscopy. Endoscopically, gastric ulcer was identified. Histological findings revealed conspicious nuclear enlargement of the non-epithelial cells in the ulcer bed, which indicated CMV infection. The patient was treated with ganciclovir for 2 weeks and the symptom was relieved. He discharged with a good renal function on day 75 posttransplant. CMV infection plays an important role in gastric ulcer after renal transplantation. Antigenemia assay dose not seem feasible for the detection of CMV-induced gastric ulcer.