BACKGROUND/AIMS: Information on prognostic factors for metastatic colorectal cancer is an important basis for planning the treatment and predicting the outcomes of the patients; however, it has not been well established. The aim of this study was to identify factors that predict results of chemotherapy and to establish a plan for treatment of patients whose tumors are inoperable due to metastatic colorectal cancer. METHODS: We conducted a retrospective review of records from 75 patients treated for colorectal cancer in Kosin University Gospel Hospital, from October 2004 to September 2008. Patients with inoperable tumors due to metastasis at the time of diagnosis who were treated with oxaliplatin or irinotecan as the first-line treatment were included in this study. We investigated the factors that might have an effect on overall survival. RESULTS: A total of 75 patients were included in this study. Results of univariate analysis showed that hemoglobin (Hb) > or =10 g/dL at the time of diagnosis, no increase in CEA on the follow-up examination after chemotherapy, chemotherapy plus surgery, and better response to chemotherapy were significant prognostic factors. Results of multivariate analysis showed that Hb > or =10 g/dL at the time of diagnosis (p<0.001), surgery after chemotherapy (p=0.001), and better response to chemotherapy (p=0.014) were significant prognostic factors. CONCLUSIONS: In this study, Hb > or =10 g/dL at the time of diagnosis, surgery after chemotherapy, and better response to chemotherapy were significant prognostic factors for metastatic colorectal cancer.