A 70-year-old man with multiple liver tumors was referred to our hospital in 2011. He was histologically diagnosed with a neuroendocrine G1 tumor (World Health Organization classification) following biopsy. He had a history of surgery for an ileal neuroendocrine tumor in 1991. Therefore, the liver tumors were diagnosed as metastases from the ileal neuroendocrine tumor. The patient was successfully treated with hepatic artery embolization, radiofrequency ablation, and octreotide. This report suggests that long-term follow-up with diagnostic imaging may be required for patients with ileal neuroendocrine tumors, even 20 years after the primary surgery.