Abstract： Objective:To investigate the effect of different body mass index categories on the prognosis of endometrial cancer in patients.Methods:A total of 100 patients with endometrial cancer who received treatment at the First People's Hospital of Jiande from January 2018 to June 2023 were included in this study. Based on different body mass index categories, they were divided into a normal group (18.50 - < 25.00 kg/m2), an overweight group (25.00-30.00 kg/m2), and an obese group (> 30.00 kg/m2). The effect of body mass index on the prognosis of endometrial cancer was analyzed.Results:The age differences among patients with different body mass index categories were statistically significant (all P < 0.05). Compared with the normal group, the age of patients in the overweight and obese groups was younger. Kaplan-Meier survival analysis showed that different body mass index categories had no significant effect on overall survival. Univariate analysis revealed that patients who were younger, had advanced tumor stages, exhibited deep muscular layer infiltration, and tested positive for pelvic lymph nodes exhibited significantly shorter overall survival compared with those without these factors (all P < 0.05). Multivariate Cox regression analysis showed that age had a certain effect on the prognosis of endometrial cancer in patients ( RR = 3.438, 95% CI: 1.404-8.421, P < 0.05). Conclusion:Body mass index has no significant effect on the prognosis of endometrial cancer. Patients who are diagnosed with endometrial cancer and have a higher body mass index tend to be notably younger than those with a lower body mass index, which could potentially be a critical factor influencing their prognosis. This needs further investigation.