Trauma has received a great deal of attention in the last years. One line of research in this field focuses on exploring the importance of personality variables in resistance and vulnerability in trauma (Beaton & Murphy, 1995; Dutton & Rubinstein, 1995; Figley, 1995). This empirical study explores the process of secondary traumatic stress among 175 sanitary professional, focusing on the contribution and the degree of relevance of personality variables, such as comprehensibility, challenge, sense of humor and empathy. Secondary traumatic stress was measured with the Secondary Traumatic Stress Measure (Moreno-Jiménez, Morante, Rodríguez and Garrosa, 2004). Results indicate these personality variables seem to have an important role in secondary traumatic stress’s process. Finally, further implications of the findings are discussed.