Although systemic multidrug chemotherapy is the first-line therapy for unresectable colorectal cancer, hepatic arterial infusion chemotherapy(HAI)may be a potential alternative treatment for patients with unresectable colorectal liver metastasis. A 65-year-old man underwent sigmoidectomy for sigmoid colon cancer with bilobar, multiple liver metastases. Postoperatively, an HAI regimen of 5-fluorouracil(5-FU, 1,000mg/m²/5 h/every week)was administered for 26 weeks; the total dose of 5-FU administered was 52 g. Complete response(CR)was achieved, according to an imaging diagnosis technique. Thereafter, the patient was followed-up in an outpatient setting, without any further anti-cancer treatment. A solitary liver metastasis was identified by using magnetic resonance imaging(MRI), 6 years 6 months after achieving CR. The patient underwent partial liver resection for the recurrent liver metastasis. Histological diagnosis revealed an adenocarcinoma, consistent with the findings for metastatic sigmoid colon cancer. The patient's postoperative recovery was uneventful, and he remains alive 5 years after liver resection, without any evidence of tumor recurrence. Further long-term follow-up might be advisable considering the slow-growing nature of this tumor.