World Health Organization estimates 34 million people were living with HIV at the end of 2011. In Poland, between 1985 and the end of 2012 16 314 cases of HIV-infected were registered. The prevalence of pain in HIV-infected patients varies between 24% and 93%. Pain syndromes seen in HIV-positive patients, can be categorized into three types: those directly related to HIV infection or consequences of immunosuppression, those caused by HIV therapies, and those unrelated to HIV infection or HIV infection therapies. HIV-infected patients often suffer from two or more pain syndromes with common prevalence of neuropathic pain. The most common pain sites are as follows: head, oral cavity, chest, abdomen, joints and muscles. Pain experienced by HIV-infected patients is very often undertreated. Opioids and adjuvants are prescribed too rarely. In this article epidemiology, patomechanism, location and causes of undertreatment of pain in HIV-infected patients were discussed.