ObjectiveTo explore the expression of human epidermal growth factor receptor 2 (HER2) and its associations with clinical, pathological, and imaging characteristics in endometrial carcinoma (EC) patients.MethodsA retrospective analysis was conducted on 214 patients with newly diagnosed EC treated at Zhongshan Hospital, Fudan University, from January 2022 to December 2024. HER2 expression was assessed using immunohistochemistry (IHC) staining, and its associations with clinical characteristics, histopathological and imaging features were analyzed.ResultsThe HER2 expression rate (IHC score of 1+/2+/3+) in EC was 37.4% (80/214). HER2 expression was significantly associated with older age, advanced International Federation of Gynecology and Obstetrics (FIGO) stage, aggressive histological types, P53abn and low apparent diffusion coefficient (ADC) of preoperative pelvic magnetic resonance imaging (MRI). Multivariate analysis indicated that aggressive histological types (P=0.002) and low ADC of preoperative pelvic MRI (P=0.047) were independent factors associated with HER2 expression.ConclusionsADC of EC lesions may serve as a non-invasive predictive marker for HER2 expression, while histological type provides a critical basis for precisely guiding HER2 testing.