Endometriosis is a common cause of chronic pelvic pain and lacks precise pathophysiological mechanisms. Advanced oxidation protein products (AOPPs), markers of oxidative stress and inflammation, are implicated in pain-related diseases and have been suggested to play a crucial role in endometriosis pathophysiology. We aim to assess the significance of AOPP in endometriosis by analyzing their levels across serum, follicular fluid, peritoneal fluid, and ovarian endometrioma tissue, and their association with different disease stages. A systematic review of articles published up to Nov 2024 examining AOPP levels in endometriosis patients compared to controls was conducted (PROSPERO: CRD42022343714). Using the Newcastle-Ottawa Scale (NOS), the quality and risk of bias of included studies were assessed, and publication bias was evaluated using Egger's and Begg's tests. The analysis 12 studies involving 561 control patients without endometriosis and 670 patients with endometriosis. Compared to controls, elevated AOPP levels were observed in endometriosis patients' serum and peritoneal fluid. Patients with type III/IV endometriosis exhibited higher AOPP levels in serum and plasma compared to control patients, suggesting a potential association with disease severity. The study underscores the potential of AOPP levels as biomarkers for endometriosis severity and proposes them as pharmacological targets for disease management, including pelvic pain treatment.