As of November 19, 2009, while the 2009 influenza A(H1N1) epidemic was just beginning in metropolitan France, the overseas territories—with the exception of Mayotte—had all emerged from the first wave. Stakeholders involved in surveillance, care, management, prevention, communication, and research in the French territories of the Southern Hemisphere (Réunion, Mayotte, New Caledonia, French Polynesia, and Wallis and Futuna), as well as in New Zealand and Australia, participated in a seminar to exchange experiences with their counterparts in metropolitan France. This seminar was jointly organized by the French Institute for Public Health Surveillance (InVS), the Directorate General for Health, and the Institute of Microbiology and Infectious Diseases (IMMI). It provided an opportunity to conduct an in-depth analysis of the dynamics and characteristics of the epidemic wave, to share the Southern Hemisphere’s response experience with their mainland counterparts, and to put this exchange of experience into perspective for the remainder of the pandemic.