Background: Caudal analgesia (CA) has been considered as a common approach used in the subumbilical region in children. Fentanyl is a potent synthetic opioid drug, but usually associated with several adverse events. On the other hand, dexmedetomidine has sedative and hypnotic actions and doesn't have adverse events on respiratory or cardiovascular (CV) functions. Objective: To evaluate safety and efficacy of caudal bupivacaine-dexametomedine and caudal bupivacaine-midazolam in ultrasound (US) guided caudal nerve block in pediatric hernioraphy. Patients and Methods: This was a clinical prospective clinical trial conducted on a total of 105 cases who were undergone herniorraphy. All patients were divided into three equal groups; control group receiving 0.2% of bupivacaine (1 mg/kg), MB group receiving 0.2% of bupivacaine (1 mg/kg) and midazolam 0.05 mg/kg and DB group receiving 0.2% of bupivacaine (1 mg/kg) and dexametomedine 0.5 mic/kg. Results: DB group and MB group were associated with significant increases in FLACC compared to the control group. DB group was accompanied by a significant increase in the time to first analgesic request and a significant decrease in total analgesic doses compared to MB group and control group. There were no statistically significant differences among the three studied group with regard to PONV. Conclusion: In the context of CA, adding dexmedetomidine or midazolam combined with bupivacaine significantly prolonged the analgesic duration, however dexmedetomidine was superior over midazolam with regard to analgesic profile without an increase in adverse events in children undergoing lower abdominal surgery.