The regional anesthesia technique which is suitable for fracture clavicle is a matter of debate. This study aimed to compare the use of superficial cervical plexus alone or in combination with interscalene block in patients undergoing internal fixation of fractured clavicle. Seventy patients undergoing internal fixation of fractured clavicle were enrolled in this clinical trial and randomly distributed into two groups; superficial cervical plexus block (CPB) group and combined superficial cervical plexus block and interscalene block (ISB) group. The regional anesthesia techniques were performed before induction of general anesthesia. The intraoperative fentanyl and isoflurane consumption, the postoperative morphine consumption, the postoperative pain score, the duration of postoperative analgesia, the incidence of perioperative complications, and the patient's satisfaction were recorded. In comparison to the use of combined CPB and ISB, the use of CPB alone did not significantly change the postoperative morphine consumption (8.4±3.3 mg versus 7.3±3.2 mg [P=0.2]), the time to the first request of postoperative analgesia (396.7 193.4 min versus 407.7±150.0 min [P=0.8]), or the postoperative pain score (P˃0.05). Also, it did not change the intraoperative fentanyl consumption (P=0.3), the intraoperative isoflurane consumption (P=0.7), the incidence of perioperative complication, or the degree of patient's satisfaction (P˃0.05). It significantly decreased the incidence of phrenic nerve palsy (P=0.03). In patients undergoing internal fixation of clavicular fracture, the perioperative analgesic effect of SCP alone is equally effective to its use in combination with ISB.