Objective: To assess the predictive value of the platelet-to-lymphocyte ratio(PLR), neutrophil-to-lymphocyte ratio(NLR)and tumor-related factors on the peritoneal metastasis in advanced gastric cancer patients. Methods: A total of 701 pathologically confirmed gastric cancer patients who underwent surgery at the First Affiliated Hospital of Wenzhou Medical University between Jan 2009 and Jan 2012 were enrolled. Results: Univariate analysis indicated that tumor location, tumor size, serosal invasion, depth of invasion, pathological type, lymph node metastasis and PLR were related to peritoneal metastasis(all P<0.05). According to the area under the ROC curve, the optimal cutoff value of PLR for predicting peritoneal metastasis was 132.43 (sensitivity 71.8%, specificity 50.6%). There were significant differences in tumor size, TNM stage, lymph node metastasis and serosal infiltration between high PLR group and low PLR group. Multivariate Logistic analyses revealed that PLR (HR=2.205, P=0.003), lymph node metastasis(HR=3.113, P=0.010)and tumor size(HR=1.150, P=0.014) were independent risk factors for peritoneal metesfasis. Conclusions Preoperative PLR is valuable in predicting peritoneal metastasis of advanced gastric cancer and it is an independent risk factor for peritoneal metastasis of gastric cancer.