Exposure to traumatic events often leads to negative psychological and behavioral consequences. Some adherents of cognitive theories indicate that dysfunctional cognitive schemas can explain the emergence and development of traumatic stress. People who hold negative beliefs about the world and their own abilities will develop symptoms of traumatic stress because their cognitive schemas generate anxiety. Our intervention aims to present the most relevant predictors of dysfunctional beliefs in medical professionals. We also highlight the results of a second own study on the association between vicarious trauma-specific dysfunctional beliefs and traumatic stress symptoms in healthcare professionals. In addition, we present some explanatory mechanisms of the relationship between dysfunctional beliefs and intrusion, one of the symptoms of traumatic stress with marked effects on medical professionals’ mental health. The results of the first study indicated that neuroticism was the strongest predictor of vicarious dysfunctional beliefs, a result consistent with previous research, followed by extraversion and conscientiousness. The regression analyzes performed in the second study showed that the dysfunctional cognitive schemas of the symptoms are significant predictors of the traumatic stress (intrusions, avoidance, hyperactivity). The multiple mediation model revealed that rumination and suppression explained the relationship between dysfunctional beliefs and traumatic stress symptoms. The results are discussed from the perspective of the increasing professional challenges in the medical field and the impact of the activity of medical professionals on sustainable development.