<p>Antebrachial fractures in captive non-human primates are challenging because unpredictable forelimb use and limited tolerance of external coaptation increase torsional loading across the radius-ulna unit. A 10-year-old, 7.8-kg male long-tailed macaque (<i>Macaca fascicularis</i>) presented with a closed distal diaphyseal oblique radial fracture and a concurrent transverse distal diaphyseal ulnar fracture of the right forelimb. No radiographic evidence of underlying osseous pathology was found. After initial medical management, open reduction and internal fixation of both bones was performed. A low-contact titanium locking plates applied as bridge plates were placed under multimodal general anaesthesia. Peripheral nerve block of the radial, ulnar, median and musculocutaneous nerves was performed. Postoperative management included cage confinement and short-term external support. Functional hand use for feeding and climbing returned by four weeks. Besides, radiographic callus formation and radiographic union with full functional recovery was documented by 14 weeks without apparent complications. This case suggests that dual-bone locked bridge plating can provide practical torsional stability in macaques, supporting timely union and early functional recovery. This may be particularly useful when prolonged external immobilisation is difficult to enforce.</p>