This study examined the protective effects of hardiness (dispositional resilience) on self-reported posttraumatic stress disorder (PTSD) symptoms in a sample of postdeployed service members. Hardiness was negatively related to PTSD symptoms. Time in the military, number of deployments, and total time spent on deployment were all positively related to PTSD symptoms. Hardiness moderated the effects of time in the military on PTSD symptoms, such that time in the military had no effect on those who were high in hardiness. Hardiness did not moderate the effects of either deployment measure. Suggestions to modify current military resilience training programs to most effectively enhance the benefits of hardiness are discussed.