Pregabalin has been available in Japan since June 2010 for neuropathic pain. The adverse effects of pregabalin might be serious, and one must start at minimal doses and increase gradually to effective doses with enough explanation to patients. Pregabalin is a derivative of y-aminobutyric acid (GABA), but it has no effects on GABA receptors. Pregabalin reduces allodynia and hyperalgesia that are main symptoms of neuropathic pain. There are reports about the supportive effects of pregabalin for perioperative analgesic action of opioids. In the spinal nerve ligation (SNL) model, mRNA of alpha2delta-1 subunit of voltage gated calcium channels (VGCCs) is increased in the dorsal root ganglion (DRG) and alpha2delta-1 subunit of the spinal dorsal horn is increased. The effects of pregabalin is to bind alpha2delta-1 subunit and normalize the numbers of VGCCs at neuron surface and decreases neurotransmission, especially by excitatory amino acid. The descending facilitating serotonergic system from rostral ventromedial medulla may have effects on the occurrence and maintenance for the chronic pain. New drugs with less adverse effects may be developed.