OBJECTIVE: To evaluate the effect of intraoperative dexamethasone on short-term clinical outcomes following decompression procedures for cubital tunnel syndrome (CuTS) and its role in controlling postoperative inflammation. METHODS: A retrospective analysis was conducted on 114 patients with severe CuTS, categorized into a dexamethasone group (n=55) and a control group (n=59). All patients underwent anterior ulnar nerve transposition. The dexamethasone group received 10 mg of dexamethasone injected subepineurally after decompression. Outcomes were assessed at 4 weeks and 6 months postoperatively using visual analog scale, patient-reported ulnar nerve evaluation, Modified Bishop score, two-point discrimination, and electromyography. RESULTS: At 4 weeks, the dexamethasone group showed significantly better improvements in visual analog scale (3.56 ± 0.88 vs. 4.03 ± 0.99, P = 0.014), patient-reported ulnar nerve evaluation (40.87 ± 7.82 vs. 43.49 ± 7.16, P = 0.045), and Bishop scores (8.69 ± 1.18 vs. 7.49 ± 0.88, P <
0.002) compared to the control group. Electrophysiological testing at 6 months also revealed higher motor nerve conduction velocity (50.04 ± 3.92 vs. 46.49 ± 4.84 m/s, P <
0.002) and sensory nerve conduction velocity (49.06 ± 4.60 vs. 47.10 ± 5.63 m/s, P = 0.041) in the dexamethasone group. No adverse effects were observed. CONCLUSIONS: Intraoperative dexamethasone effectively reduces inflammation and edema, promoting early nerve recovery and improved short-term outcomes in CuTS decompression. It is a safe and effective adjunctive treatment strategy.