: Olecranon fractures are common injuries of the upper limb in adults. Simple displaced trasverse fractures are generally surgically treated with tension-band wiring (TBW) or plate fixation (PF). The purpose of this retrospective study is to compare the clinical-functional outcome, complications and reoperation rates between TBW and PF for Mayo IIA fractures. : 72 patients treated with PF or TBW at our institution, completed our survey and clinical evaluation and their demographic and clinical data were recorded and analysed. The clinical-functional outcomes were evaluated assessing ROMs and three validated scoring systems: the Disabilities of the Arm, Shoulder, and Hand (DASH), the Mayo Elbow Performance Score (MEPS) and the Patient American Shoulder and Elbow Surgeons Standardized Elbow Assessment score (pASES-e). : 38 patients (53%) underwent TBW and 34 (47%) PF. The mean DASH, MEPS and pASES-e scores were respectively 14.5 ± 17.2, 80.5 ± 14.7 and 83.6 ± 12.4 in the TBW group and 21 ± 21.7, 75.6 ± 15.3 and 75.1 ± 19.2 in the PF group ( = 0.16, = 0.17 and = 0.03). The mean duration of surgery and hospitalisation period were longer in the PF group ( = 0.002, = 0.37) whereas the complication and reoperation rates were higher after TBW ( = 0.15, = 0.24). : According to the literature, both TBW and PF resulted comparable valid surgical options for the treatment of simple isolated displaced olecranon fractures. Our results corroborate previous findings, showing good/excellent outcomes without significant differences.