The aim of this study was to evaluate the clinical significance of the granulocyte-to-lymphocyte(G/L)ratio as a prognostic predictor in patients with Stage IV colorectal cancer. A total of 83 patients who underwent oxaliplatin-based chemotherapy for Stage IV colorectal cancer were enrolled in the study. Univariate analysis indicated that the G/L ratio; number of involved organs(more than one organ); performance status ≥1; noncurability; and levels of hemoglobin, C-reactive protein, albumin, alkaline phosphatase, carbohydrate antigen 19-9, and lactate dehydrogenase before chemotherapy were significant prognostic factors. Noncurability was identified to be an independent, unfavorable factor for survival on multivariate analysis. When patients were divided into 2 groups according to the G/L ratio(the median was considered the cut-off value), the median survival time of patients with a high G/L ratio(≥3.0)was significantly worse than that of patients with a low G/L ratio(<3.0; 16.1 months vs 25.4 months, p=0.03). Further studies with more patients are required to examine whether the G/L ratio is a convenient biomarker affecting survival in patients with Stage IV colorectal cancer.