The article summarizes the findings from an evaluation of Operation Restore, a brief posttrauma intervention developed for first responders. Participants were 207 police officers, firefighters, emergency services personnel, 911 operators/dispatchers, and Federal Bureau of Investigation agents, exposed to job-related critical incidents. These first responders participated in 1 of 35 deliveries of Operation Restore between 2013 and 2018. A mixed-methods pre/post follow-up evaluation design was used to assess changes in first responders’ scores on a posttraumatic outcome measure and to obtain their qualitative feedback. Significant growth (p < .001) was observed in all domains on the posttraumatic measure following participation in Operation Restore; effect sizes were large (Cohen’s d = .80–1.5). In all, 92% of the first responders experienced positive growth post retreat. With the exception of the personal strength domain, changes in scores at the 90-day follow-up assessment did not significantly decline from postretreat levels, and the effect size associated with the loss in personal strength was small (d = .30). In addition, changes in posttraumatic growth were not associated with participant sex, race/ethnicity, occupation, or veteran status, providing evidence that the intervention was appropriate for a broad range of participants. Qualitative findings supported the quantitative results and revealed that first responders could better handle their emotions following the retreat. The initial evaluation results provide support regarding the effectiveness of Operation Restore. Continued evaluation of the program and building on opportunities to strengthen and expand the design will serve to increase our understanding of this program.