Background: Head and neck injuries are common in football. Injuries such as concussion can have serious consequences. Previous studies have shown that size and function of trunk muscles are predictive of lower limb injuries in professional Australian Football League (AFL) players. It is unknown whether measurement of trunk muscles can also be used to predict head and neck injuries. Objectives: To examine whether trunk muscle measurements predict head and neck injuries incurred by professional AFL players. Design: Prospective cohort study. Method: Ultrasound imaging of trunk muscles was performed on 165 professional AFL players at the start of the pre-season and 168 players at the start of the playing season. Injury data were obtained from records collected by the AFL club staff during the playing season. Results/findings: The ability to contract the multifidus (MF) muscle at the L5/S1 vertebral level at the start of pre-season and start of the playing season predicted head and neck injury in the playing season. Sensitivity and specificity of the model were 56.3% and 76.6% for the pre-season and 50.0% and 77.2% for the playing season respectively. Conclusions: A model with potential clinical utility was developed for prediction of head and neck injuries in AFL players. These predictive values will need to be validated in other teams. Ability to contract MF is modifiable and this information could be incorporated into pre-season injury prevention programs.