Background: Detailed descriptions of the relationship between lymphocyte-to-monocyte ratio alone and combined with CA125 (COLC) and advanced stage of ovarian cancer (OC) have been lacking to date. This study is to analyze the relationship between LMR, CA125 and COLC and advanced stage of OC.Methods: A retrospective clinicopathologic review was performed. The receiver-operating characteristic (ROC) curves of LMR, CA125, and COLC staging OC were constructed. Furthermore, a binary logistic regression model was used to assay the independent risk factors.Results: A total of 225 patients with OC were identified in this cohort. Eighty-five patients with OC were diagnosed at an early stage, and 140 OC patients were diagnosed at an advanced stage. The median of LMR at the early stage was higher than the advanced stage (4.39 vs. 2.78), and the median of CA125 was lower than the advanced stage (80 U/mL vs. 251.25 U/mL). Multivariate logistic regression indicated that LMR (OR=0.314, 95% confidence interval [CI]: 0.143–0.687, P=0.004) and CA125 (OR=4.045, 95%CI: 1.883–8.692, P<0.001) were associated with OC staging. Furthermore, the area under the curve of COLC was higher than that of LMR (0.779 vs. 0.732) or CA125 (0.779 vs. 0.708) in staging OC. The specificity of COLC was higher than that of LMR (87.11% vs. 70.61%) or CA125 (87.11% vs. 61.21%) in staging OC.Conclusions: LMR alone or in combination with CA125 might be associated with OC staging. Besides, as a predictive factor, COLC may have high specificity in staging OC.