Abstract: Objective: To assess if posttraumatic stress disorder (PTSD), recognized as a common mental disorder in the general population and veteran samples, has a unique impact on comorbidity, disability, and suicidal behavior (after adjusting for other mental disorders, especially depression). Methods: Data came from the Canadian Community Health Survey Cycle 1.2 (n = 36,984; age ≥15 years; response rate 77%). All respondents were asked if they had been given a diagnosis of PTSD by a healthcare professional. A select number of mental disorders were assessed by the Composite International Diagnostic Interview. Chronic physical health conditions, measures of quality of life, disability, and suicidal behavior were also assessed. Results: The prevalence of PTSD as diagnosed by health professionals was 1.0% (95% CI = 0.90–1.15). After adjusting for sociodemographic factors and other mental disorders, PTSD remained significantly associated with several physical health problems including cardiovascular diseases, respiratory diseases, chronic pain conditions, gastrointestinal illnesses, and cancer. After adjusting for sociodemographic factors, mental disorders, and severity of physical disorders, PTSD was associated with suicide attempts, poor quality of life, and short- and long-term disability. Conclusions: PTSD was uniquely associated with several physical disorders, disability, and suicidal behavior. Increased early recognition and treatment of PTSD are warranted. PTSD = posttraumatic stress disorder; CCHS 1.2 = Canadian Community Health Survey cycle 1.2; CI = confidence interval; WBMMS = Psychological Well-Being Manifestation Scale.