Nie D, et al. - Whether thrombocytosis has any prognostic value in endometrial carcinoma (EC) was investigated by analyzing relevant literature identified from database including PubMed, MEDLINE, EMBASE, and Web of Science. They assessed the correlation between thrombocytosis and overall survival (OS) and disease-free survival (DFS) by using the hazard ratio (HR), odds ratios with 95% confidence intervals (CIs). They also focused on the link between thrombocytosis and patient clinicopathological features. Also, publication bias and sensitivity analysis were carried out. The analysis involved 11 studies, with a total of 3,439 patients. Findings demonstrated a significant association of pretreatment thrombocytosis with a decreased OS (pooled HR = 2.99; 95% CI = 2.35–3.8; P < 0.001) and DFS (pooled HR = 2.86; 95% CI = 2.27–3.6; P < 0.001) in patients with EC. Moreover, its correlation with adverse clinicopathological parameters was also observed. Overall, pretreatment thrombocytosis was identified as an adverse prognostic marker in patients with EC.