While existing literature suggests an association between polycystic ovarian syndrome (PCOS) and endometrial cancer, the sparsity and inconsistency of current evidence indicates a lack of clarity regarding the exact strength of this association. It also remains uncertain whether the degree of risk of disease is affected by confounding factors, such as age and body mass index (BMI). The present meta-analysis is aimed to quantify the risk of endometrial cancer in female subjects with PCOS compared to those without PCOS. PubMed, MEDLINE, EMBASE, Scopus and Cochrane were searched from inception to October 31, 2022, to identify peer-reviewed case-control, cohort and cross-sectional studies that assessed the association between endometrial cancer and PCOS and contained original data. Two researchers independently extracted data and performed quality assessment using the Newcastle-Ottawa criteria. Pooled odds ratios (ORs) were calculated using the random-effect model and inverse variance. The degree of heterogeneity was assessed using I 2 statistics. A total of 10 relevant studies were identified and included in the meta-analysis (comprising 12,248 female patients with PCOS and 54,120 controls). Females with PCOS had a significantly increased odds of developing endometrial cancer as compared to those without PCOS [OR, 4.07; 95% confidence interval (CI), 2.13-7.78; P<0.0001]. When postmenopausal subjects (age, >54 years) were excluded from the meta-analysis, the odds increased further (OR, 5.14; 95% CI, 3.22-8.21; P<0.00001). Patients with PCOS are up to 5 times more likely to develop endometrial cancer compared to those without PCOS. Larger, prospective studies that are well-controlled for confounding factors, such as BMI, are required.