Objective: To describe clinical presentation and initial management of patients with deltoid ligament ankle sprains. Design: Retrospective. Setting: Practice-based research network. Participants: Athletic trainers (n = 133) from 52 clinics in 19 states. Independent Variable: Deltoid sprains (October 2009–April 2020). Main Outcome Measurements: Clinical findings (e.g., sport, mechanism of injury, severity, range of motion, tests) and initial management. Results: Deltoid sprains (n = 105) were diagnosed within 3.2 ± 4.1 days of injury, mostly in male secondary school athletes (n = 62/105, 59.0%). Common sports were football (n = 29/94, 30.9%) and basketball (n = 28/94, 29.8%). Common mechanism of injuries were twisting (n = 35/94, 37.2%) and contact (n = 28/94, 29.8%). Sprains were mostly mild (n = 59/94, 62.7%) with mild or no edema (n = 85/96, 85.5%) and effusion (n = 90/96, 93.4%). Active (n = 49/96, 51.0%) and passive range of motion (n = 54/96, 56.3%) were mostly normal, and a median of four (interquartile range = 2–5) tests were used, mostly anterior drawer (n = 74/105, 70.5%) and talar tilt-eversion (n = 74/105, 70.5%). Management involved removal from participation (n = 48/94, 51.1%), treatment by athletic trainers (n = 22/40, 55.0%), and referral to physicians (n = 16/40, 40.0%). Conclusions: Deltoid sprains mostly occurred in males playing football or basketball and were caused by twisting with minimal effusion, edema, and range of motion loss. Given the infrequency of deltoid sprains and difficulty diagnosing them, thorough clinical evaluation is necessary for treatment decisions.