Studies of oxaliplatin, 5-fluorouracil and leucovorin in pretreated metastatic colorectal cancer showed that oxaliplatin dose intensity is important prognostic factor for objective response rates and progression-free-survival (PFS). To evaluate response rates, PFS and toxicity according to oxaliplatin dose intensity, we retrospectively analyzed data from patients with metastatic colorectal cancer received oxaliplatin,5-fluorouracil, leucovorin regimens. Sixty-three patients were reviewed in this study, 42 patients received low dose intensity oxaliplatin (LDI: $leq85;mg/m^2/2wks$) and 21 patients high dose intensity oxaliplatin (HDI: $>85;mg/m^2/2wks$). Objective responses occurred in 10 $(47.7\%)$ HDI patients and 9 $(21.4\%)$ LDI patients (p = 0.014). Median PFS was 24.7 weeks in HDI group, with $45.1\%$ of HDI patients progression free at 6 months, and 20.5 weeks in LDI group, with $33.5\%$ of LDI patients progression free at 6 months (p = 0.344). Increased oxaliplatin dose intensity was not associated with neutropenia, thrombocytopenia, neuropathy, nausea and vomiting. This study showed that oxaliplatin dose intensification significantly improves objective response rate in pretreated metastatic colorectal cancer without increasing severe toxicity.