Dexamethasone (0, 0.25, 1, 5, 10, and 20 mg/kg) by itself failed to significantly attenuate the frequency of cisplatin-induced (20 mg/kg) emesis. Δ9-THC by itself significantly reduced the frequency of emesis produced by cisplatin in a dose-dependent manner. At the doses tested, Δ9-THC had no significant additive or synergistic antiemetic activity with dexamethasone. *Significantly different from 0 mg/kg Δ9-THC control group for the corresponding dexamethasone doses, p<0.05.