Oxaliplatin has been used as a first choice for colorectal, gastric and pancreatic cancer, but it induces peripheral neuropathies. Dimethyl fumarate (DMF) is an oral drug for multiple sclerosis with neuroprotective effects on oxidative stress. Using both in vivo and in vitro models, we investigated the effects of DMF on oxaliplatin-induced peripheral neuropathy and other side effects, as well as on the anti-tumor activity of oxaliplatin. Repeated intraperitoneal injection of 4 mg/kg oxaliplatin (twice per week for 4 weeks) caused mechanical allodynia (as revealed by the von Frey tests), cold hyperalgesia (as revealed by the acetone tests), and axonal degeneration in the sciatic nerve of rats. Co-administration of oral DMF (200 mg/kg, five times per week for 4 weeks) relieved oxaliplatin-induced mechanical allodynia but not cold hyperalgesia, and ameliorated axonal degeneration. In addition, DMF did not exacerbate oxaliplatin-induced body weight loss or bone marrow suppression, such as reduction in red blood cells, white blood cells, neutrophils and lymphocytes. Furthermore, DMF did not inhibit the anti-tumor activity of oxaliplatin in any cultured cancer cell line (C26, mouse colon carcinoma; HCT116, human colon carcinoma; MKN45, human gastric adenocarcinoma; MIA PaCa-2, human pancreatic carcinoma) or C26-bearing mice. These results suggest that DMF prevents oxaliplatin-induced mechanical allodynia and axonal degeneration without affecting the anti-tumor activity of oxaliplatin. Therefore, DMF may be useful for managing oxaliplatin-induced chronic peripheral neuropathy.