ObjectiveTo compare the outcomes between patients undergoing surgery for ruptured endometrioma versus non-ruptured endometrioma. Study DesignThe study was conducted at Health Sciences University, Etlik Zübeyde Hanım Training and Research Hospital Infertility Clinic. All patients who had a histopathology report of endometrioma between January 2014 and December 2020 were recruited. Patient files, surgery notes and laboratory values were extracted from the electronic recording system and patients with ruptured endometriomas (RE) or non-ruptured endometriomas (NRE) were compared. ResultsOverall, 181 patients were recruited to the study. No rupture was detected in 146 (80.7 %) patients while 35 patients (19.3 %) underwent surgery for RE. Pre-operative CRP, CA 125, CA 19–9, CA 15–3, CEA and mean platelet volume (MPV) values and postoperative MPV and neutrophil/lymphocyte ratio (NLR) values were statistically significantly higher (p < 0.01) in the RE group compared to the NRE group. Post-operative lymphocyte (p = 0.029) and eosinophyl (p = 0.015) values were significantly lower in the RE group compared to the NRE group. Among the preoperative biomarkers that are evaluated for prediction of rupture; MPV, CA 19–9 and CA-15.3 had a high specifity (>75 %) but a rather low sensitivity (<60 %), meanwhile CRP, CA-125 and CEA had high sensitivity but a low specifity. ConclusionRE patients had significantly higher preoperative CRP, CA 125, CA 19–9, CA 15–3, CEA, and MPV values and postoperative MPV and NLR values while postoperative, lymphocyte and eosinophyl values were significantly lower compared with the NRE patients. Prospective studies with larger sample sizes are needed to determine biomarkers and parameters that can be used for non-invasive diagnosis of endometriosis and predict the possibility of endometrioma rupture.