Although gagging is a frequent problem that, when severe, can jeopardize the dental procedure, no single protocol is used to alleviate this phenomenon. Selective 5-HT 3 antagonists, such as granisetron, may attenuate gagging. In this study, granisetron and placebo were administered intravenously, in a crossover, doubleblind manner, to 25 healthy volunteers in 2 different sessions. Gagging levels were recorded before and after administration, as were BP, pulse, and O 2 saturation. Recorded results were analyzed with the use of tests for nonparametric values (P 5 .05). A significant increase in the depth of swab insertion was noted after administration of both placebo and drug. The increase in drug effectiveness correlated with decreased body weight. The true efficacy of granisetron in gagger patients with this treatment protocol has yet to be fully established, although it has been theorized that an increased dosage of granisetron may have a better effect.