Oral corticosteroids (OCS) are frequently prescribed by otolaryngologists. However, there are limited quantitative data on OCS-related adverse events (AEs) in otolaryngology. We sought to quantify OCS-related AEs in otolaryngology. All outpatient otolaryngology encounters in our healthcare system (2018-2023) at which an OCS was prescribed were identified via the electronic medical record. The diagnoses indicating OCS were categorized as sinonasal, otologic, pharyngo-laryngeal, and other. The medical record was subsequently examined to assess for OCS AEs during the 21-day period following the prescription. OCS AEs were grouped into (1) gastrointestinal, (2) metabolic, (3) bone/muscle, (4) ophthalmologic, and/or (5) psychiatric complications. The frequency and types of OCS related AEs were determined. A total of 20 746 otolaryngology encounters with OCS prescribed were examined. Seventy OCS courses had 1 or more AEs, implying a number needed to harm of 296.4 (240.2-386.8). There were 83 total OCS-related AEs, yielding an AE incidence rate of 4.0:1000 (95% CI, 3.0-5.0:1000) OCS prescriptions. The mean age of subjects with AEs (61.5 years) was significantly higher than those without (50.3 years; P < .001). Forty-seven (56.6%) of the complications were metabolic, with hyperglycemia and hypokalemia the most common, followed by gastrointestinal (26.5%), ophthalmologic (3.6%), psychiatric (2.4%), and musculoskeletal (2.4%). AEs related to OCS prescribed by otolaryngologists occur at a rate of once per 296 courses of treatment and older populations may be at increased risk for AEs. Otolaryngologists should balance AE rates against anticipated benefits of steroid therapy. 3.