There has been increased interest in self-perceived posttraumatic growth, but few longitudinal studies have focused on its relationship with posttraumatic stress. Self-perceived growth is generally thought to facilitate adjustment, but some researchers have proposed that it reflects a dysfunctional coping strategy that impedes adjustment and leads to posttraumatic stress. In this prospective longitudinal study, we examined the relationship between self-perceived posttraumatic growth and stress. Participants were soldiers deployed to Iraq. They were tested before their deployment (N = 479) and again 5 months (n = 382; 80%) and 15 months (n = 331; 69%) after returning home. Cross-lagged panel analysis indicated that more perceived growth 5 months postdeployment was associated with more posttraumatic stress 15 months postdeployment, even after we controlled for stressor severity, posttraumatic stress at 5 months, and potential predeployment confounders (extraversion, neuroticism, and cognitive ability). Findings suggest that it may be counterproductive to promote perceived growth to enhance adjustment after traumatic events.