The explosion at the AZF factory on September 21, 2001, in Toulouse had a major impact on the entire city, both in terms of human casualties (30 deaths, several thousand injured) and property damage (damaged buildings). A cross-sectional survey was conducted 18 months after the explosion among a representative sample of adults living in the city at the time of the accident, in the nearby area particularly affected and in the rest of the city (distant area), to assess the medium- and long-term consequences of this industrial disaster on physical and mental health, particularly symptoms of post-traumatic stress disorder and depression. Nearly all residents of the near zone and nearly half of those in the far zone reported damage to their homes. One in four people located within 1,700 meters of the explosion reported being injured, and the main physical sequelae reported involved hearing problems. The prevalence of mental health disorders was high, particularly in the near zone, where 19% of women and 8% of men reported symptoms of post-traumatic stress disorder, high scores on depression scales, and high use of psychotropic medications. In the immediate vicinity, these symptoms were more frequent among those who had been more exposed to the explosion—whether immediately (proximity, personal physical injuries, or injuries to others) or later (e.g., financial difficulties)—and among those who were older, female, and had a history of psychiatric disorders and more unfavorable socioeconomic characteristics. This study highlights the lasting impact of an industrial disaster on residents’ mental health, particularly in the immediate vicinity, by revealing the extent and diversity of psychological consequences that persist several months after the explosion. It underscores the need to adapt and improve care systems (hearing screening, psychological support), especially for the most disadvantaged populations. Finally, it highlights the need to improve the epidemiological approach to disasters. (R.A.)