BACKGROUND: Anticonvulsant agents have been used and found to be effective for the treatment of neuropathic pain. Even though it is rare, they can have very serious side effects and therefore the search for more selective drugs with fewer side effects is justified. This study was conducted to evaluate the newly introduced anticonvulsants, gabapentin, for various neuropathic pain syndromes in the Korean population. METHODS: According to individual diagnostic group as diabetic neuropathy, postherpetic neuralgia, chronic back pain with radiating pain, there were 20 patients per group. Patients have been stabilized in their analgesic regimen at least four weeks prior to enrollment in the study. An anticonvulsant, if taken, was discontinued for four weeks for wash-out. Pretreatment baseline pain scores (visual analog scale and a pain intensity score) were obtained. Oral administration of gabapentin 300 mg was initiated in all groups and doses were given from 300 mg per day with gradual titration over two weeks 1) to the maximum of 2400 mg per day, 2) to the onset of intolerable side effects, and 3) to the onset of analgesic effect. At two weeks follow-up visit, visual analog scale, pain intensity scores, pain improvement scores judged by family, drug efficacy, tolerability and overall evaluation were assessed. The incidence of side effects, cell blood count and chemistry were also obtained. RESULTS: After two weeks of treatment, the visual analog scale and pain intensity scores improved in all study groups and no patients experienced aggravation. These findings were objectively reflected in pain improvement scores observed by family members. In drug efficacy, tolerability and overall evaluation, the majority of patients scored as good or excellent. There were no reports of serious side effects. Minor side effects were spontaneously subsided even with continuation. CONCLUSIONS: Gabapentin, a newer anticonvulsant, appears to be effective as an adjunctive analgesic for the management of various neuropathic pain syndromes with minimal side effects.