Exercise training positively impacts mental health, yet remains untested in older adults with posttraumatic stress disorder (PTSD). We conducted a randomized controlled pilot trial to test the feasibility and acceptability of exercise training in older veterans with PTSD. Fifty-four veterans ≥ 60 years, with a DSM-V diagnosis of PTSD, were randomized to supervised exercise (n = 36) or wait-list (WL; n = 18). Primary outcomes included recruitment rates, attendance, satisfaction, and retention. Secondary outcomes included changes in PTSD symptoms, depression, health-related quality of life, and sleep quality; assessed at baseline and 12 weeks. There were no adverse events. Attrition was minimal (14%), and adherence to the exercise intervention was high (82%). Clinically significant improvements in PTSD and related conditions were observed following exercise (Cohen's d = 0.36-0.81). Exercise training is safe and acceptable in older adults with PTSD, may improve PTSD symptoms, and broadly impacts PTSD-related conditions. Future definitive trials are warranted.