Background: Changed adjuvants have been used to extend regional blockage, shorten onset times of blocks and prolong time of post-operative analgesia. Objectives: This study aimed to compare the effect of dexamethasone plus bupivacaine versus fentanyl plus bupivacaine in ultrasound guided supra-clavicular approach of the brachial plexus block for upper limb surgeries. Subjects &Methods: A prospective randomized double-blind research that was conducted in the South Valley University Hospital, Qena, Egypt. The study included 90 patients of both sexes, scheduled for upper limb surgeries (Orthopedic and plastic surgeries). Result: Regarding onset of sensory block (min) it was minor in fentanyl category followed by dexamethasone category & longer in control category with important differences. Complete sensory block (min) occurred in shorter period in fentanyl group then in dexamethasone group and took longer period to occur in control group with significant difference. Time of sensory block (hr) was longer among dexamethasone group followed by fentanyl group and less period in control with significant difference. Conclusion:The addition of dexamethasone or fentanyl to bupivacaine in supraclavicular brachial plexus block was safe in terms of hemodynamic stability and side effects, and significantly prolongs time of sensory & motor block & reduces VAS scores.