Due to high incidence and survival rates of prostate cancer, mental and physical health outcomes of prostate cancer survivors are important public health issues. Some men with prostate cancer experience positive psychological changes known as posttraumatic growth (PTG), which could operate through psychophysiologic pathways to buffer against negative effects of stress and facilitate health behavior change. However, scant research has tested outcomes of PTG. This longitudinal study therefore examined PTG as a moderator for multiple indicators of mental and physical health in a sample of Black and White prostate cancer survivors (N=168) with heterogeneous socioeconomic status. In multivariate analyses, PTG moderated negative effects of initial cancer-related worry on later happiness and mental quality of life, and PTG demonstrated significant, positive main effects on life satisfaction and perceived health. PTG was not significantly related to physical quality of life, cancer-related symptoms, or health behaviors (i.e., exercise, diet, alcohol, sleep). Because this study was not powered to detect small effects, larger samples may reveal additional effects of PTG. Future studies should continue to examine outcomes related to PTG in diverse samples of cancer survivors, using objective measures when possible. In addition, interventions are needed to improve and sustain health behaviors among prostate cancer survivors, many of whom fail to meet recommended levels of physical activity and fruit and vegetable consumption, regardless of their levels of PTG.