The purpose of this study was to explore the influence of psychosocial factors and psychological flexibility on rehabilitation protocol adherence in a sample of injured collegiate athletes. Self-report measures were given to injured athletes before the start of a physical rehabilitation protocol. Upon completion of rehabilitation, each athlete was assessed by the chief athletic trainer using a measure of rehabilitation adherence. Correlational analyses and bootstrapped logistic regression analyses were conducted to determine whether broad psychosocial factors and level of psychological flexibility predicted engagement and adherence to a rehabilitation protocol. Psychological flexibility, as measured on the Acceptance and Action Questionnaire (2nd ed.; Bond et al., 2011), contributed significantly to the overall logistic regression model. Study findings suggested that assessment of psychological flexibility could give medical providers a way to evaluate both quickly and quantitatively potentially problematic behavioral responding among injured athletes, allowing for more effective adherence monitoring.