The growing prevalence of Secondary Traumatic Stress (STS) among mental health professionals (MHPs) has contributed to an ongoing mental health workforce shortage in the United States. Literature has shown strong evidence of workforce and organizational risk factors for STS, with inconsistent conclusions about the role of personal trauma. Previous research has relied on the 2004 Secondary Traumatic Stress Scale without consideration of updated posttraumatic stress disorder diagnostic criteria. The present study explored the relationship between adverse childhood experiences (ACEs) and STS among MHPs and whether rates vary across mental health disciplines. MHPs (n = 222) from 10 disciplines completed demographics, ACEs, and STS measures. Results found a weak, positive correlation and predictive relationship between ACE and STS scores. Further, no statistically significant difference existed between ACE and STS scores among disciplines. Given the high rates of mental health symptoms and growing need for services, more research is needed to better understand how to recruit and retain MHPs for the betterment of client outcomes. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]