A regional analysis of brain benzodiazepine (BDZ) receptors was conducted in narcoleptic and normal dogs to determine whether these sites are altered in narcolepsy. It was postulated that BDZ receptors play a role in the excessive sleepiness of narcolepsy because activation of these sites in freely behaving normal animals is hypnogenic. [3H]Flunitrazepam binding sites were assessed in 11 discrete areas of the forebrain and brainstem. No consistent or statistically significant group differences in either receptor densities (Bmax) or binding affinities (Kd) were found. These findings do not support the assertion that BDZ receptors are involved in the pathogenesis of canine narcolepsy.