Chemokines are small proteins belonging to the family of inflammatory cytokines whose main property is to attract and activate immune cells. Chemokines produce their biological activity by interacting with receptors belonging to the family of G protein-coupled receptors (GPCR). It is now clearly demonstrated that, under non-pathological conditions, chemokines and their receptors are constitutively expressed in the nervous system. Exploration of the implication of chemokines and their receptors in pain is a rapidly expanding domain of research. Recent results demonstrate that chemokines are active as modulators of nociceptive information both in the peripheral and central nervous system. After a brief recall of the chemokinergic system, we will discuss recent work on CCL2, a chemo-attractive cytokine which binds to the CCR2 receptor. There is a large body of data supporting the hypothesis that the CCL2 chemokine, released in the dorsal horn of the spinal cord, could have a direct effect on the transmission of nociceptive information and thus participate in neuronal adaptation and probably in the plasticity of glial cells and attractivity of immune cells observed during the installation and development of chronic pain arising from an inflammatory and/or neuropathic mechanism.