Objective To evaluate the effect of propofol, sevoflurane, and dexmedetomidine on respiratory complications in children undergoing fiberoptic bronchoscopy(FOB). Methods This double-blind randomized clinical trial was conducted among 120 children aged 1 month to 3 years undergoing FOB. The patients were randomized into 3 groups(n=40) for anesthesia induction with sevoflurane inhalation, 1 mg/kg propofol, or 1 μg/kg dexmedetomidine before bronchoscopy, and the changes in hemodynamic parameters, sedation level, and respiratory complications during and after the procedure were assessed. Results The patients' heart rate during bronchoscopy was significantly lower and the mean arterial blood pressure significantly higher in dexmedetomidine group than in sevoflurane and propofol groups(P<0.05). Cough during bronchoscopy did not occur in any of the cases in propofol group, while the highest frequency of cough was recorded in dexmedetomidine group. The incidence of laryngospasm in the propofol group(12.5%) was significantly lower than those in sevoflurane and dexmedetomidine groups(30% and 32.5%, respectively)(P<0.05). Conclusion Sevoflurane and propofol are safe and suitable for anesthesia induction in children below 3 years of age undergoing diagnostic FOB and can achieve better sedative effect and lower the incidences of cough and respiratory complications as compared with dexmedetomidine.