Context: Although the pathogenesis of endometriosis is still largely unknown, several studies have demonstrated the potential role of ovarian steroids hormone in the growth of endometriotic cells. Furthermore other hormones could be involved in the pathogenesis of endometriosis: an increase of stress-related hormones such as DHEA and DHEA-S was found. This evidence could explain the alteration of immune response in endometriosis. Objective-Interventions: To evaluate plasmatic and salivary levels of DHEA and DHEA-S in women with endometriosis in order to understand if such steroids may have, directly or indirectly, a possible supporting role in the pathogenesis and progression of this disease. We examined saliva because it contains the not-protein bound form of DHEA and DHEA-S (the biologically active form of steroids). Methods-Patients: DHEA and DHEA-S in plasma and in saliva were assessed in 20 women suffering from endometriosis aged 23-36 years and in 21 healthy women aged 21-30 years, both in follicular and luteal phase. Results: Our data show that both salivary and circulating DHEA and DHEA-S levels are significantly higher (p < 0,05) in women affected by endometriosis in comparison with healthy subjects. Furthermore DHEA and DHEA-S levels are significantly higher during follicular phase than luteal one. Conclusions: These results could likely be due to an increased activity of hypothalamus-pituitary-adrenal axis leading to increased production of adrenal DHEA and DHEAS. Considering that DHEA and DHEA-S can be converted periferically and centrally in biological active estrogens and since estrogens regulate the growth of ectopic endometrial tissue, our data may further contribute to explain the pathophysiology of endometriosis.