Objective: Trampoline-related injuries have increased in South Korea. However, little research has been conducted on this topic. This study aimed to show the characteristics of pediatric trampoline-related injuries in South Korea and to investigate the factors associated with admission. Methods: A retrospective, cross-sectional study was conducted using data from South Korea’s Emergency Department-based Injury In-depth Surveillance registry for dates between January 2011 and December 2016. All patients under 18 years of age with trampoline-related injuries were included. We divided the patients into two groups based on whether they were admitted or discharged. Odds ratios with 95% confidence intervals were calculated to evaluate the factors associated with hospital admission for pediatric trampoline-related injuries. Results: A total of 2,745 patients were enrolled and the incidence increased over time (P for trend<0.01). The most common injury site was the lower extremity (45%). Fracture was the most frequent diagnosis (34.3%). Compared to the discharge group, the adjusted odds ratios (95% confidence intervals) for hospital admission were 3.53 (1.73–7.17) for the teenage group, 2.62 (1.82–3.77) for upper extremity injuries, 18.48 (7.95–42.95) for fractures, 2.28 (1.35–3.86) for falls, and 2.04 (1.15–3.60) for collisions. Conclusion Trampoline-related injuries in children have increased over time in South Korea. Most occur in children under the age of 12 years, but children between the ages of 13 and 18 years are at a higher risk for hospitalization. Also, injuries of the upper extremity, fracture, falling, and collision are risk factors for admission. Preventive strategies are needed to reduce trampoline-related injuries in children.