A woman in her 80s had two episodes of ileus, which led to the diagnosis of advanced jejunal cancer. She was diagnosed with Lynch syndrome when she was in her 60s, for which she underwent annual follow-up with computed tomography for 8 years. Unfortunately, she died from the recurrence of jejunal cancer and liver metastases. Jejunal cancer is relatively rare in Lynch syndrome, and no surveillance strategy has been established for small bowel cancer. In patients with unexplained abdominal complaints, small bowel cancer should be considered.