Objective: Few longitudinal studies have examined the relationship between trauma exposure and posttraumatic stress disorder (PTSD) in relation to quality of life or have been designed to consider the relationships between trauma, PTSD diagnosis, and quality of life in terms of both global scores and specific domains. This article aims to provide an essential longitudinal examination of the effects of trauma and PTSD diagnosis on global as well as specific domains of quality of life in a Canadian sample to better understand the diagnosis and unveil possible routes of research and successful treatment methods for the future. Method: Data were drawn from the initial two waves of the Zone d’étude en épidémiologie sociale et psychiatrique du sud-ouest de Montréal (ZEPSOM), an epidemiological catchment area study based in southwest Montréal (N = 2,433 at Wave 1 and N = 1,823 at Wave 2). PTSD diagnosis and global and subscale scores of quality of life outcomes were established by face-to-face structured interviews using standardized instruments. Outcomes were compared among 3 trauma/PTSD categories and healthy controls. Results: This study extends previous cross-sectional findings within the catchment area by demonstrating that the effects of current PTSD diagnosis on quality of life endure with time. Specifically, the negative impact of current diagnosis of PTSD on Wave 2 quality of life is expressed through its influence on Wave 1 quality of life. Subscale findings are discussed. Conclusion: Research needs to focus on understanding more than just global indices of quality of life when it comes to the trauma spectrum. Additional research remains necessary to fully understand these complex relationships over time.