Treatment of radial neck fractures (RNFs) in children, particularly those with severe displacement or angulation, remains controversial, largely due to the challenge of achieving optimal reduction without resorting to open reduction. This study aimed to assess the outcomes of ultrasonography (US)-guided percutaneous leverage reduction coupled with US-guided fixation using either elastic stable intramedullary nail (ESIN) or Kirschner wire (KW) for severely displaced Judet type III and IV RNFs in children. We hypothesized that both strategies would be effective and aimed to identify the superior approach. A total of 38 pediatric patients presenting with Judet type III and IV RNFs resulting from falls were treated surgically between January 2020 and January 2022. The cohort comprised 15 boys and 23 girls, aged on average 7.6 ± 2.3 (range: 2.8–11.3 years). The fractures were classified as type III (n = 28) and type IV (n = 10). The patients were divided into 2 treatment groups: ESIN group (n = 15; treated with US-guided percutaneous leverage reduction and ESIN fixation) and the KW group (n = 23; treated with US-guided percutaneous leverage reduction and KW fixation). Variables such as surgical time, frequency of intraoperative radiography, fracture healing time, hospitalization costs, radiographic outcomes, and functional elbow scores were analyzed. Most fractures demonstrated both clinical and radiographic evidence of complete healing within 7 weeks. Based on the Tibone and Stoltz classification (Tibone J, Stoltz M. Fractures of the radial head and neck in children. J Bone Joint Surg Am. 1981;63:100–6), almost all patients had excellent or good clinical outcomes, with only one exception in the ESIN group. The KW group exhibited significantly lower hospitalization costs compared to the ESIN group [(9562.6 vs 12,043.6 + 7694.0)¥, P < .05]. Both groups required notably few intraoperative radiographic exposures (KW: 5.4 ± 2.1 times, ESIN: 4.0 ± 1.9 times, P < .05). No major complications were reported. However, one case of ESIN displacement and joint protrusion was noted. Our study suggests that US-guided percutaneous leverage reduction, combined with either ESIN or KW fixation, is an effective treatment for severely displaced radial neck fractures in children. Both treatment modalities resulted in notably few intraoperative radiographic exposures and yielded favorable clinical and radiological outcomes. The integration of US-guided leverage reduction and KW fixation is both cost-effective and safe.