Influenza is a viral respiratory disease capable of causing epidemics that represent a threat for global security. Mexico was the first country to notify the WHO of an outbreak of what later became the first influenza pandemic of the 21st Century, caused by the virus A(H1N1)2009. Before this event Mexico had a national pandemic influenza preparedness plan, which included seasonal influenza vaccination, stockpiles of personal protection equipment and strategic drugs, and risk communication strategies. During the epidemic, the national public health laboratory network and case surveillance systems were strengthened together with surge capacities for intensive care and delivery of antiviral drugs. Risk communication was conducted for people to comply with implemented measures regarding social distancing (workplace and school closures, household quarantine). This report describes the Mexican experience during the 2009 influenza pandemic and the lessons that this experience provides to public health preparedness for future pandemics.