To determine if dexamethasone is more effective than the combination of dexamethasone plus dimenhydrinate in the antiemetic prophylaxis of patients in ambulatory otorhinolaryngological surgery in the Víctor Lazarte Echegaray Hospital. Material and methods: Analytical, observational, retrospective cohort study in 80 patients according to selection criteria that were divided into 2 groups of 40 patients according to administration regimen: dexamethasone or dexamethasone plus dimenhydrinate Results: The frequencies of nausea, vomiting and need for rescue medication in the user group of dexamethasone and dexamethasone plus dimenhydrinate were 12.5%, 5%, 5% and 10%, 2.5%, 2.5% respectively. The averages of time to onset of nausea in the user group of dexamethasone and dexamethasone plus dimenhydrinate were: 128 mins. and 127.5 mins respectively. Conclusions: There were no significant differe...