Although rare, gastrointestinal posttransplant lymphoproliferative disorder (PTLD) can lead to abdominal pain or gastrointestinal bleeding in patients with a history of solid-organ transplantation. We describe a case of isolated gastrointestinal PTLD in a patient who presented with acute on chronic iron deficiency anemia 26 years after heart transplant. A comprehensive endoscopic evaluation with video capsule endoscopy and small bowel enteroscopy revealed a large cratered ulceration in the small bowel with abnormal mucosal changes, which led to the diagnosis of PTLD.