Pain is a multidimensional subjective experience mediated by emotion, attitudes and other perceptual influences. The functional deficit of patients suffering from pain could be expressed by a cognitive complaint. In this paper, cognitive repercussions of pain, associated factors and iatrogenic factors are presented. According to all the relation between pain and cognition seems complex and involves factors such as depression, anxiety, and medical treatment among others. All these factors interact together and produce a specific cognitive complaint for each patient.