The present study examined long-term mental health outcomes following a major disaster, including the relative risks (RR) of developing psychiatric disorders. Trauma exposure and predisaster vulnerability factors were examined as predictors of chronic psychopathology. Standardized questionnaires measuring psychological distress were completed 5() months, 14 months, 5 years, and 27 years after the disaster. Twenty seven years after the disaster, 48 (79%) survivors and a matched comparison group of 62 (78%) nondisaster-exposed controls were assessed using the Structured Clinical Interview for DSM-IV, axis I Disorders. The prevalence of posttraumatic stress disorder among the survivors was 6.1%, and the risk of having a psychiatric disorder was more than 3 times higher than in the comparison group (RR = 3.44, 95% confidence interval = 1.6–7.6). Disaster exposure and general neurotic personality predicted chronic psychopathology, which was reported by 20.9% of the participants. Findings from this study suggest that increased risk of psychopathology persists 27 years after disaster. Both disaster exposure and vulnerable personality are important predictors of chronic psychopathology.