The involvement of bulbospinal pathways in the antinociceptive effect of clomipramine in experimental pain was studied. The antinociceptive effect of the antidepressant (0.5 mg/kg), intravenously injected, was evaluated after a unilateral lesion of the dorsolateral funiculus. The results showed that this effect was suppressed only in the hindpaw ipsilateral to the dorsolateral funiculus lesion, and suggest that the antinociceptive effect of antidepressants needs intact descending inhibitory bulbospinal pathways.