This study was planned to evaluate the preventive effect of dexamethasone for sore throat after ambulatory laryngeal microsurgery. One hundred and ten patients scheduled for ambulatory laryngeal microsurgery under general anesthesia were randomly divided into two groups, group S1 and group D1. Patients in the group D1 were injected with 0.2 mg/kg of intravenous dexamethasone before the induction of anesthesia. The incidences and severities of sore throat were measured using verbal rating scale (VRS) at 1 h and through phone calls at 6 h after the operation. The patients who requested analgesics in the recovery room were measured VRS shortly before administration of medicine. The patients in group S1 and group D1 who did not receive rescue analgesics were enrolled in group S6 and group D6, respectively, and evaluated 6 h after the surgery. There were no significant differences in the incidence and severity scores of sore throat during 1 h after the end of operation between group S1 and group D1. But at 6 h, the patients in the group D6 had lower incidence of sore throat than those in group S6 significantly (P = 0.003). Furthermore, the patients in the group D6 had lower severity of sore throat than those in group S6 significantly at 6 h (P = 0.001). In conclusion, prophylactic administration of intravenous dexamethasone is appeared to have efficacy for the management of sore throat in the early post-discharge period following ambulatory laryngeal microsurgery.