Background: Conservative treatment remains the preferred choice for distal radius fracture in children. However, loss of reduction is problematic, especially in an older child. Crossed Kirschner-wires is widely used to treat distal radius fracture in adolescents. This study aimed to compare the application of crossed Kirschner-wiring (KW) and non-bridging external fixator (EF) for the treatment of delayed distal radial fracture involving metaphyseal diaphyseal junction (MDJ) in adolescents. Methods: Between January 2012 to January 2017, 146 (male = 101, female = 45) patients in EF group and 117 (male = 76, female = 41) in KW group, were reviewed retrospectively. Preoperative data were collected from the hospital database, and postoperative clinical outcomes data were collected during the follow-up visits. We used SPSS for data analysis. Results: There existed no significant difference between EF and KW regarding sex, body weight, fracture side, duration from injury to surgery. The duration of surgery was significantly shorter in EF (30.5 ± 6.1 min) than the KW group (44.6 ± 9.4 min), P < 0.001. The number of intraoperative X-ray images was significantly lower in EF (6.5 ± 1.1) than KW (11.8 ± 2.3), P < 0.001. The incidence of tendon irritation is significantly higher in the KW (19.7%) than the EF group (0%), P < 0.001. The residual angulation on the AP view was higher in KW (3.8 ± 2.3, degrees) than the EF group (2.5 ± 1.6, degrees), P < 0.001. The volar tilting is better in EF (6.6 ± 1.1, degrees) than the KW group (1.0 ± 1.5, degrees), P < 0.001. However, the functional outcomes of the wrist showed no significant difference between EF and KW group, P = 0.086. Conclusion: The EF was superior to KW in the treatment of radial MDJ fractures in adolescents. The EF displayed shorter duration of surgery, less tendon irritation, and better radiographic outcomes than the KW. However, the cost-effect analysis remains to be investigated, because the EF is more expensive than KW.