BACKGROUND. Police officers are exposed daily to high levels of organizational and operational stressors that have a negative impact on health and well-being outcomes. This population has elevated rates of cardiovascular disease, sleep disorders, symptoms of depression and post-traumatic stress disorder (PTSD), and suicide. Although there are few empirically supported effective stress reduction interventions in police officers, recent evidence suggests that an 8-week training program in mindfulness meditation, specifically tailored for this group, has promise in reducing perceived stress and improving stress-related physical and mental health outcomes including sleep disturbances, anxiety, depression, and burnout. The primary aims of the current study were to 1) demonstrate the feasibility, acceptability, and adherence of a similar mindfulness training program in a new population of police officers; 2) replicate previously demonstrated improvements in perceived stress and stress-related health outcomes, and 3) provide novel evidence of hypothesized reductions in symptoms of PTSD.METHODS. We enrolled 30 sworn law enforcement personnel from a mid-sized, Midwestern U.S. police department in an 8-week, group-based mindfulness training program. We conducted in-person assessments immediately before and after the training program, consisting of self-report measures of perceived stress, sleep quality, physical and mental health symptoms, and burnout and the assessment of high-sensitivity C-reactive protein (hs-CRP) and other physical health measures. An abbreviated remote assessment at 5-month follow-up included self-report measures only.RESULTS. All 30 officers completed the 8-week program and both in-person assessments, with high rates of class attendance, substantial out-of-class practice time, and uniformly positive evaluations of the training program and instructors. Replicating previous studies, we identified post-training reductions in perceived organizational and operational stress, global sleep disturbances, anxiety, and burnout, with significant reductions in anxiety and perceived stress observed at 5-month follow-up. We also identified novel evidence for reduced PTSD hyperarousal symptoms that persisted at 5-month follow-up, and reduced re-experiencing PTSD symptoms at 5-month follow-up only. There was no evidence for changes in self-reported physical health symptoms or hs-CRP.CONCLUSIONS. Successful adaptation, delivery, and acceptance of this mindfulness-based intervention demonstrates the generalizability of mindfulness training across law enforcement populations. The replication of improved stress-related outcomes, and novel evidence for reduced PTSD symptoms, indicate important targets to be further investigated in larger, mechanistic, randomized controlled trials of mindfulness training in police officers.