The prognostic and clinicopathological role of pretreatment thrombocytosis in cancer has been widely studied, but conclusions in endometrial cancer (EnCa) remain controversial. Therefore, we conducted a meta-analysis to assess the pathologic and prognostic impacts of pretreatment thrombocytosis in patients with EnCa. We searched PubMed, Embase, SpringerLink, ScienceDirect and China National Knowledge Infrastructure databases. Pooled HR or OR with their 95% CIs were applied to assess the association of pretreatment thrombocytosis with survival outcomes and clinical parameters of EnCa patients. In total, 10 studies containing 2,995 cases of EnCa met the criteria. The results suggested that pretreatment thrombocytosis was significantly associated with high International Federation of Gynecology and Obstetrics (FIGO) stage (pooled OR 3.45, 95% CI 1.68-7.08, =0.001), poor tumor differentiation (pooled OR 2.00, 95% CI 1.22-3.29, =0.006), lymph-vascular space invasion (pooled OR 2.04, 95% CI 1.35-3.07, =0.001); myometrial invasion (pooled OR 2.14, 95% CI 1.39-3.32, =0.001); cervical involvement (pooled OR 2.54, 95% CI 1.56-4.15, =0.000) and lymph node metastasis (OR 3.15, 95% CI 1.71-5.80, =0.001). No significant difference existed between pretreatment thrombocytosis and overall survival (=0.012), cancer/disease-specific survival (=0.07) or disease-free survival (=0.25). pretreatment thrombocytosis was associated with advanced clinicopathological features in patients with EnCa, which may serve as a potential therapeutic target for EnCa.