Objective To evaluate the efficacy and safety of ultrasound-guided brachial plexus block in anesthesia for upperlimb fracture surgery. Methods Ninety patients undergoing upper-limb fracture surgery at Xun County People’s Hospital between January 2022 and December 2024 were randomly assigned to a control group or an observation group, with 45 patients in each group. The control group received anatomical landmark-guided brachial plexus block, whereas the observation group received ultrasound-guided brachial plexus block. Anesthesia-related outcomes, procedural indicators, postoperative analgesia and recovery, and complications were compared. Exploratory analyses were conducted after stratification by fracture type and puncture approach. Results Compared with the control group, the observation group had shorter block onset and complete block times, a higher first-attempt puncture success rate, fewer punctures, and a shorter operative time (all P＜0.05). NRS scores at 2, 6, 12, 24, 48, and 72 h after surgery were lower in the observation group (all P＜0.05). The first request for rescue analgesia occurred later, total analgesic consumption was lower, and the times to basic and complete functional recovery of the affected limb were shorter (all P＜0.05). Exploratory stratified analyses showed that in the three fracture type subgroups, block onset and complete block times were shorter in the observation group (all P＜0.001); as well as higher firstattempt success rates and fewer punctures within the interscalene groove and axillary approach subgroups (all P＜0.05). The overall complication rate was 2.22% in the observation group and 13.33% in the control group; the difference was not statistically significant (P＝ 0.110). No serious or delayed complications occurred in either group. Conclusion Ultrasound-guided brachial plexus block may improve anesthetic efficiency and procedural success, enhance perioperative analgesia, and facilitate early functional recovery in upper-limb fracture surgery. The direction of benefit was consistent across the exploratory subgroups, whereas a reduction in complication risk requires confirmation in larger studies.