Essential oils from fresh leaves of Eucalyptus urophylla (EOEU) and E. brassiana (EOEB), obtained by hydrodistillation, were orally administered to Swiss male mice 60 min before experimental procedures. EOEU and EOEB at either 200 or 400 mg/kg were evaluated for sedative/hypnotic activity through pentobarbital sleeping time, locomotor activity by open-field procedure, and anticonvulsant activity through seizures induced by pentylenetetrazole. EOEU and EOEB were effective in increasing the sleeping time, as well as diminishing ambulation in the open-field test. In addition, EOEU (but not EOEB) significantly increased the number of mice protected against PTZ-induced death. Our results are in accord with the ethnopharmacological use of Eucalyptus species, and, after complementary toxicological studies, could support further investigations to assess their use as sedative agents.