The aim of this study is to compare the effect of warm bupivacaine 0.5% at 37◦C versus bupivacaine 0.5% at operating room temperature at 23◦C on ultrasound-guided supraclavicular plexus block characteristics as regard sensory block onset time, motor block onset time, duration of sensory and motor block , effective duration of analgesia, total analgesics requirement, complications and side effects.