Objective: The aim of this review is to sum up the present information about opioid - induced endocrinopathy and to try to give some recommendations about how to diagnose and treat this condition in a clinical practice. Background: Chronic pain is a growing common health problem in our society and the prescription of opioids has increased in the last few years. The use of opioids is not anymore limited to only palliative care and the treatment of acute pain, but is now also used to treat chronic non-malignant pain. Opioid - induced endocrinopathy is a common, but often undiagnosed, complication of long-term opioid therapy. Method: The project is based on original and review articles in medical journals, obtained through a literature search performed in March 2013 in the database MEDLINE. A total of 31 articles were included. Results and conclusion: Research has documented that opioids alter the hormonal axes and reduce the levels of the gonadotropins, testosterone, estradiol and DHEAS. This can induce a clinical condition termed hypogonadism that causes symptoms like reduced libido, infertility, fatigue, depression, anxiety, muscle atrophy, hot flashes, osteoporosis and impotence in men and menstrual irregularities in women. Based on the high prevalence of hypogonadism patients should be routinely screened for such symptoms. Laboratory tests should be taken to confirm the clinical suspicion. As of today, there are no evidence based guidelines for the treatment of opioid – induced endocrinopathy. Management options recommended in the literature include, discontinuing opioid therapy, reducing the opioid dose, switching to a different opioid, and hormone substitution. Testosterone supplementation is the primary treatment for men. Women are conventionally treated with estrogen, progestin or DHEA substitution, or with oral contraceptives.