Objectives: Medical providers working with trauma survivors are exposed to the negative and positive effects of secondary trauma, both of which are affected by social support and job satisfaction. The aim of this study was to determine the mediating role of job satisfaction in the relationship between social support and the negative and positive effects of secondary exposure to trauma among medical personnel. The negative indicator of such exposure was secondary traumatic stress (STS), while the positive indicator was secondary posttraumatic growth (SPTG). Material and Methods: The analyses included 419 medical providers working with trauma victims (201 paramedics and 218 nurses). Data was collected with the Secondary Traumatic Stress Inventory, Secondary Posttraumatic Growth Inventory, Social Support Scale, Work Satisfaction Scale, and survey. Mediation analyses were applied to assess relationships between variables. Results: The mediation analyses indicated that job satisfaction mediates (mainly partly) the relationship between social support and STS and SPTG. This may indicate that both social support and job satisfaction act as significant predictors of the negative and positive effects of secondary exposure to trauma. Conclusions: As a friendly and mutually-supportive environment can increase job satisfaction, reducing the risk of secondary traumatic stress and promoting positive posttraumatic changes, it is important to increase social support and job satisfaction among medical providers exposed to secondary trauma. Int J Occup Med Environ Health. 2023;36(4):505–16