In light of the influenza A (H1N1) pandemic, the Strategic Advisory Group of Experts on Immunization of the World Health Organization requested that the acute flaccid paralysis surveillance system of Latin American and the Caribbean be used to establish Guillain-Barré syndrome incidence rates. An analysis was conducted of 10,486 acute flaccid paralysis cases diagnosed as Guillain-Barré syndrome from 2000 through 2008 in children aged <15 years in Latin American and the Caribbean countries and territories. The average incidence was 0.82 cases per 100,000 children aged <15 years (range, 0.72-0.90 cases per 100,000 children), with significant differences between northern and southern countries (1.08 vs 0.57 cases per 100,000 children). The acute flaccid paralysis surveillance system represents a useful means of monitoring Guillain-Barré syndrome during the pandemic.