Background <p>Intramedullary nailing (IMN) is less commonly used than plate osteosynthesis for distal humeral diaphyseal fractures because of technical challenges and fluoroscopic requirements. However, advances in implant design and internal locking mechanisms may improve the applicability of IMN in extra-articular distal humeral fractures.</p> Aims <p>This study aimed to compare the clinical and functional outcomes of lateral locking plate fixation and intramedullary nailing in AO/OTA 12&#xa0;A-C(c) extra-articular distal humeral fractures.</p> Methods <p>This retrospective cohort study included patients who underwent surgical fixation for extra-articular distal humeral fractures between 2010 and 2020. Patients were treated with either lateral locking plate fixation or intramedullary nailing. Demographic variables, operative time, length of hospital stay, time to radiographic union, shoulder and elbow range of motion, and validated functional outcome scores were compared between groups.</p> Results <p>A total of 55 patients were included, with 29 treated using plate fixation and 26 treated using intramedullary nailing. The groups were comparable regarding age, follow-up duration, and baseline demographic characteristics. No significant differences were observed in union time or functional outcome scores. However, the IMN group demonstrated significantly shorter operative times and hospital stays, as well as greater postoperative elbow flexion angles (<i>p</i> &lt; 0.05).</p> Conclusions <p>Intramedullary nailing represents a viable alternative to plate fixation for extra-articular distal humeral fractures. IMN was associated with shorter operative time and reduced hospital stay, while union time and functional outcomes were comparable between groups. Although elbow flexion was statistically higher in the IMN group, the absolute difference was small.</p>