Abstract: Post operative complications of tonsillectomy include insufficient oral feeding, pain, nausea, vomiting and bleeding. The aim of this study is to investigate the further effect of Dexametasone in case of its post operation continuation up to 24 h on its complications. In a double blind clinical trial study, 103 patients in age 3-14 year that had indication of tonsillectomy were enrolled to study and tonsillectomy was performed by single surgeon in the same surgical and anesthetic single dose of Dexametasone administrated for all patients and in Dexametasone group patients administration of Dexametasone continued q6h up to 24 h post operatively and then patients compared as Postoperative complications. Finding results showed that incidence of vomiting and pain score was significantly lower in Dexametasone group patients. Continuous of Dexametasone q6h up to 24 compared to single dose of Dexametasone more reduce Postoperative complications and oral feeding started earlier in Dexametasone group and delay discharge in Dexametasone group were lower than control group.