The French Institute for Public Health Surveillance, in collaboration with the Midi-Pyrénées Regional Directorate for Health and Social Affairs and all partners of the AZF Epidemiological Monitoring Committee, organized a symposium on October 20, 2006, in Toulouse on the theme: "Public health surveillance following a disaster: what did we learn from the AZF factory explosion?" The objective of this symposium was to present the lessons learned from the disaster in order to generate ideas for how epidemiology can better contribute to the management of an industrial accident or disaster. This symposium was intended for professionals (in health care, social services, emergency response, and civil protection, among others) and individuals from the Midi-Pyrénées region who were involved in the AZF accident, as well as, more generally, professionals concerned with the public health management of such a major accident. (R.A.)