Introduction: Endometriosis is an inflammatory disorder characterized by the growth of endometrial tissue in extrauterine locations. Ovarian endometriomas are a common form of endometriosis. Late diagnosis is the main problem in the pathology; thus, it is important to identify clinical biomarkers. Ecto-nucleotidases are enzymes that hydrolyze extracellular ATP to adenosine and are involved in many inflammatory processes. Alterations of ecto-nucleotidase activity are related to inflammatory disease states.