PROBLEM: The aim of the study was to identify if (i) psychosocial factors differ in endometriosis; (ii) related psychosocial aspects alter immune markers of depression/sickness behaviour; and (iii) serum immune marker may be indicative for endometriosis. METHOD OF STUDY: We enrolled 103 women in a case-control study. Psychosocial data were obtained, serum levels of interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, interferon (IFN)-gamma, TNF-alpha, IFN-alpha and soluble intercellular adhesion molecule-1 (sICAM-1) were analysed. RESULTS: Among 69 eligible patients, endometriosis was diagnosed in 38 women. Patients with endometriosis reported reduced quality of life, increased stress perception/depressive symptoms; the Th1/Th2 ratio was in favour of Th1, accompanied by the increased levels of IFN-alpha. sICAM-1 levels were unaffected. No correlation could be confirmed between psychosocial and immune markers. CONCLUSION: Women with endometriosis may benefit from strategies contributing to reduction of stress and development of coping mechanisms, thus helping to break the vicious circle of inflammation, sickness behaviour and depression.