Abstract Rectal temperature as well as unconditioned activity in an open-field (O-F) arena,and palpation-induced vocalization were examined in rats treated intraperitoneally with cannabinol (CBN, 17.5 or 56 mg/kg) and cannabidiol (CBD, 10 or 30 mg/kg), either singly or in combination. CBN singly resulted in hypothermia which was not attenuated by the addition of CBD. CBN reduced ambulation and rearing activities as compared to vehicle-treated rats. CBD in combination with CBN did not attenuate these effects; the CBD doees in themselves appeared inactive. Vocalization occured to a significantly greater extent in the CBN singly-treated rats as compared to the controls and the CBD singly-treated rats. Thus, CBD did not counteract the temperature and open-field effects induced by CBN. This is discussed in relation to previous results from drug discrimination experiments.