To investigate the factors related to endometrial cancer (EC) in postmenopausal women with endometrial thickening and the value of endometrial thickness (ET) in predicting EC.A retrospective study of 385 referrals to our department for hysteroscopic diagnostic curettage assessment was carried out. Univariate analysis and multiple logistic regression analysis were used to identify the independent contributors to the development of EC. The ability of ET to predict EC was evaluated by receiver operating characteristic curve analysis.The follow-up period from the identification of endometrial thickening to pathological confirmation of EC was from 2 weeks to 3 months. In the postmenopausal bleeding (PMB) group, a total of 47 participants' specimens were pathologically malignant. Older age and polypoid mass-like lesions ( P < 0.001) were independent factors associated with EC. The optimal critical value of ET in predicting EC was 9.5 mm, with a sensitivity and specificity of 70.21% and 70.67%, respectively. In the non-PMB group, six participants had evidence of malignant pathology, and only polypoid mass-like lesions were an independent factor associated with EC ( P < 0.001).For postmenopausal women with increased ET and PMB, older age, thicker ET, and polypoid mass-like lesions on transvaginal ultrasound were independent associated factors for EC. An ET greater than 9.5 mm is a threshold for predicting EC. For postmenopausal women with increased ET without PMB, the incidence of endometrial malignancy is low. If the woman has polypoid mass-like lesions on transvaginal ultrasound, she should receive further attention.Copyright © 2023 by The North American Menopause Society.