Objective: To evaluate predictive factors between serum inflammatory markers and malignancy potential of endometrium. Methods: This retrospective study was conducted at the gynecological oncology unit, department of obstetrics and gynecology, at the faculty of medicine of Thammasat University. The study period was from 2017 to 2020. Endometrial cancer and benign gynecologic disease cases who underwent hysterectomy (with or without adnexectomy) during the study period were recruited. Demographic characteristics, histopathology reports and serum markers were also collected. Results: The study included a study group of 49 participants with endometrial cancer and a control group consisting of 119 cases of benign uterine disease. The study group had statistically significantly higher mean ages, proportional menopausal status and instances of underlying diseases when compared with the control group. Neutrophil/Lymphocyte ratios (NLR) and Platelet/Lymphocyte ratios (PLR) could not meaningfully predict the malignant potential of endometrium in hysterectomy specimens. NLR and PLR were statistically associated with depth of myometrial invasion (MI) in endometrial cancer cases. NLR equal to or greater than 1.93 predicted MI more than half thickness with sensitivity, specificity, accuracy, positive (PPV) and negative predictive value (NPV) at a percentage of 83.3, 52.8, 37.0, 90.5 and 60.4, respectively. PLR equal to or greater than 134.95 predicted MI of greater than fifty percent thickness with sensitivity, specificity, accuracy, PPV and NPV at 75.0, 55.6, 36.0, 87.0 and 60.4 percent, respectively. Conclusion: NLR and PLR have positive associations with myometrial invasion of endometrial cancer.