Endometrial polyp (EP) is a condition that is often encountered in obstetrics and gynecology clinic practices. In our study, we aimed to reveal the relationship between prolidase enzyme activity (PEA) and Oxidative Stress (OS) in patients with endometrial polyps. Thirty-five patients who were histopathologically diagnosed with EP and 35 patients with abnormal uterine bleeding (AUB) without pathology as a result of endometrial sampling were included in the control group. Serum TOS, OSI, tissue PEA, and endometrial thickness values were found to be statistically significantly higher in the EP group compared to the control group. We believe that our study, when supported by studies with larger patient groups, may be a useful marker for a more detailed understanding of the pathogenesis and clinical follow-up of patients.