Objective. To determine if the anticonvulsant gabapentin has an analgesic effect in human benign nociceptive pain. Design. A double-blind, placebo-controlled, cross-over study. Subjects. 30 adult patients with chronic interspinous ligament pain. Interventions. 6-week treatment period, 1 week washout, 6 week treatment. Patients received gabapentin 300 mg daily, increasing by 300 mg weekly to a total daily dose of 15 mg kg(-1) to nearest 300 mg, or equal number of placebo capsules: after washout period those who started on placebo received gabapentin, those on gabapentin received placebo. Outcome measures. Analgesic efficacy, mobility, analgesic consumption and patient preference for study medication were assessed. Results. 24 of 30 completed the study. Pain scores fell from 7.10 (95% confidence limits 6.26-7.94) in week 1 to 6.39 (95% confidence limits 5.39-7.39) during the 6th week of gabapentin treatment (P < 0.05). Analgesic consumption was unchanged with gabapentin but increased with placebo (P < 0.05). Mobility increased during gabapentin treatment (P < 0.01). One patient wished to continue on placebo, eight wished to continue gabapentin. Four patients out of 24 derived more than 50% pain relief with gabapentin. Conclusion. Gabapentin reduces chronic benign nociceptive pain and increases mobility.