This study aims to provide a basis for introducing domestic safety standards aligned with the international standards of the World Forum for Harmonization of Vehicle Regulations (WP.29) through an analysis of injuries sustained by occupants of large size vehicles and to serve as foundational data. We analyzed 4,712 cases from the ‘Korean In-Depth Accident Study (KIDAS)’ data, collected from four Emergency Medical Centers from January 1, 2011, to December 31, 2022. Among these, we identified the primary injury sites of large size vehicle occupants by reviewing their MAIS (Maximum Abbreviated Injury Scale) and examined the types of injuries at these sites. Additionally, we conducted a t-test to compare the mean ISS (Injury Severity Score) of occupants in large and non-large size vehicles. The primary injury sites for large size vehicle occupants were, in order of frequency, the Extremities, Abdomen, Head & Neck, External, Thorax, and Face. In the upper Extremities, Scapula fractures occurred most frequently, followed by Clavicle and Radius fractures, which occurred at the same frequency. In the lower Extremities, fractures of the Pelvic Ring, Femur, Tibia, and Fibula occurred with equal frequency. The injury with the highest severity was a Pelvic Ring fracture with an AIS score of 5. The ISS was 10.65±9.45 for large size vehicles and 7.04±1.36 for non-large size vehicles, with a t-value of -3.568 and a p-value of 0.089. Through this study, we identified the primary injury sites and types of injuries for occupants of large size vehicles, and we found that the injury severity of occupants in large size vehicles is higher than that of occupants in non-large size vehicles. This is a simple comparison that excludes factors such as road conditions and vehicle safety features; therefore, additional research is needed to aid in the introduction of safety standards for large size vehicles that align with international guidelines.