Introduction. The antiepileptic drug gabapentin has begun to be used successfully in some cases of neuropathic pain. Its mechanism of action is still unknown, but seems to be related to a positive effect on the synthesis and liberation of the neurotransmitter GABA. Clinical cases. Based on the observations of other authors, we used this drug in dosage varying between 900 and 1,200 mg/day in three patients with neuropathic pain, of both central and peripheral origin, and in whom the usual treatment had been unsatisfactory or could not be tolerated because of side-effects, The patients had been diagnosed as having trigeminal neuralgia, post-herpetic neuralgia in the area of the first branch of the trigeminal nerve and a thalamic infarct which gave rise to a contralateral Dejerine-Roussy syndrome, respectively. In all three cases, administration of gabapentin was followed by such a striking improvement of the pain that co-adjuvant treatment could be reduced or stopped, with excellent tolerance and a minimal incidence of side-effects. Conclusions. Gabapentin should be borne in mind in the treatment of this type of pain, particularly when the usual treatment cannot be given or is insufficient to control pain,especially in elderly patients in whom there is often reduced tolerance of drugs.