A 71-year-old man presented with sigmoid colon cancer and multiple unresectable liver metastases. As the sigmoid colon cancer caused anemia, we performed laparoscopic-assisted sigmoidectomy prior to the administration of systemic chemotherapy. Bevacizumab (Bv) plus modified Leucovorin, 5-fluorouracil, and oxaliplatin (mFOLFOX6) was administered as first line therapy.At 3 months from the start of chemotherapy, computed tomography revealed that the size of the liver metastases reduced by 49.45%, as evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines (version 1.1). The only adverse event observed was Grade 1 peripheral neuropathy after the eighth dose of oxaliplatin.As the progression of peripheral neuropathy was observed at the ninth dose of oxaliplatin, oxaliplatin was omitted from further therapy; the patient was converted to maintenance therapy with simplified biweekly Leucovorin and fluorouracil (sLV5FU2). Bv plus mFOLFOX6 followed by sLV5FU2 for first-line therapy was effective for disease management over 23 months, but a partial response (PR) was the best overall response achieved.