The purpose of this study was to compare the effectiveness and recovery times of 0.3 and 0.5 mg/kg intranasal midazolam (INM) administered with a mucosal atomizer device (MAD) in a pediatric emergency dental hospital clinic. One hundred eighteen children aged from 4 to 6 years were randomly administered either 0.3 or 0.5 mg/kg INM via an MAD in a triple-blinded randomized controlled trial. Sedation was achieved to some degree in 100% of the sample. The pulse rate and oxygen saturation were within the normal range in 99% of the patients. A burning sensation was reported in 9% of children. The recovery time of the 0.5 mg/kg group was statistically longer than that of the 0.3 mg/kg group (16.5 vs 18.8 minutes) but the difference was not clinically significant. The findings of this study show that 0.3 or 0.5 mg/kg doses of INM resulted in safe and effective sedation. The 0.5 mg/kg dose was more effective than the 0.3 mg/kg dose in reducing anxiety.