Aim: The basic aim was to find a non-invasive procedure to diagnose and monitor endometriosis-adenomyosis. Materials and Methods: A prospective study was carried out. The authors conducted a series of 60 consecutive patients who underwent diagnostic laparoscopy for benign gynecologic conditions. Endometrial, peripheral blood and peritoneal lavage samples were analyzed. IL-6, IL-16, TNF-alpha, and LIF levels were measured and compared. Results: The authors analyzed clinical data of 52 patients (26 endometriosis, 13 adenomyosis, and 13 control group). Peritoneal fluid IL-6 is significantly higher in stage IV endometriosis group than the control group (p = 0.001). In the endometriosis group, the levels of TNF-alpha in the peritoneal fluid was higher than the control group (p = 0.008). In the endometriosis and adenomyosis groups, the levels of IL-16 in the peritoneal fluid were significantly higher than the control group (p = 0.000 and p = 0.002). Conclusions: Significant immune-inflammatory changes were observed. When the underlying molecular mechanisms will be investigated, this will elicit studies on the immunotherapeutic treatment of endometriosis. Further studies are needed to assess various potential therapeutic interests for biomarkers in a large, well-defined patient population.