On April 22, 2009, the WHO issued an international alert regarding cases of human infection with a new influenza A(H1N1)2009 virus, initially observed in Mexico and later in the United States. The geographic spread of infected cases then extended throughout North America and rapidly reached Oceania, Asia, and Europe. The population’s very low immunity to this new virus was the cause of its increased circulation. Knowledge gained from the three pandemics of the last century indicated that attack rates were approximately three times higher than those observed during seasonal flu outbreaks. This 2009 influenza A(H1N1) pandemic thus represented an unusual situation that required the implementation of a specific organizational structure, comparable to a crisis response system. The French management and surveillance system was established on an emergency basis, based on the government plan developed for the H5N1 avian influenza virus. This pandemic plan, designed to respond to a highly virulent avian-origin threat, was activated for the first time for the A(H1N1)2009 virus. Following the emergence of the first cases of influenza A(H1N1)2009, a surveillance system specific to influenza A(H1N1)2009 was established by the French Institute for Public Health Surveillance. This surveillance had to adapt and evolve throughout the various phases of the epidemic. This article presents the major stages of this surveillance, along with the methods used and the main results in the Midi-Pyrénées region.