Thailand has the highest rate of motorcycle fatalities globally, with motorcycles involved in 74.4% of fatal accidents. Different crash scenarios result in varying kinematic and injury responses in motorcyclists. A comprehensive understanding of the relationship between motorcycle accident parameters and motorcyclist injuries is crucial for developing effective countermeasures and vehicle safety solutions. This study examines the association between various accident parameters and the severity of motorcyclist injuries in motorcycle-vehicle collisions. Common crash scenarios were categorized into three distinct scenarios and two configurations based on 228 Thailand accident reports. Key accident parameters, including impact speed, angle, and point of impact, were identified and analyzed. Multibody dynamics simulation was employed to reconstruct motorcycle accidents and define parameter boundaries. These models were then used to generate possible accident cases based on real-world accident scenarios. In total, 1,011 impact conditions were simulated to estimate head injury criteria and chest acceleration. The C4.5 decision tree was employed to analyze the association between the accident parameters and motorcyclist injury. The results show sufficient predictive abilities. Impact angle was the most influential factor in predicting head and chest injuries. In the motorcycle impacting car configuration, motorcycle speed and the opponent vehicle’s impact point affected predictions of head and chest injuries, while opponent vehicle speed was influential for predicting chest injuries. In the car impacting motorcycle configuration, opponent vehicle speed and the motorcycle’s impact point affected predictions of head and chest injuries, while opponent vehicle impact point was influential for predicting head injuries.