Several methods have been reported for treating avian antebrachial fractures, yet the quantitative information regarding their success is limited. This retrospective study applied data from raptors admitted to a wildlife rehabilitation center to provide metrics associated with the treatment of ulna fractures with an intact radius by either conservative management or a single surgical method: a type I external skeletal fixator tied in to an intramedullary pin (ESF IMP tie-in). Postfledging wild raptors with an ulna fracture admitted to The Raptor Center at the University of Minnesota College of Veterinary Medicine (St Paul, MN, USA) between January 1, 2007, and December 31, 2017, that survived for at least 7 days after admission were included in the study. Information regarding signalment, fracture characteristics, treatment method, outcome, and complications were recorded. The study included 110 raptors representing 15 species. The majority of birds (69%, 76/110) were treated with conservative management. Conservative management was used more often in cases of chronic (P = .02) and closed (P = .02) fractures, whereas fractures with poor alignment at the time of admission were frequently treated through surgical means (P=.001). Alignment was more likely to improve with an ESF IMP tie-in (P=1.01 ×10^–9). The majority of cases (65%, 72/110) had a successful outcome. Birds with closed fractures were more likely to have a successful outcome (P=.03). Birds in which fracture alignment became exacerbated with either treatment method were more likely to have a poor outcome (P=.002). The results of this retrospective study found that conservative management and surgical fixation by the ESF IMP tie-in technique are both viable treatment options for ulna fractures with an intact radius in raptors. The choice of treatment method is dependent on the clinician's assessment of the fracture characteristics and individual patient.