The 21st Annual Latin American Symposium presented by the American Mosquito Control Association (AMCA) was held as part of the 77th Annual Meeting in Anaheim, CA, in March 2011. The principal objective, as for the previous 20 symposia, was to promote participation in the AMCA by vector control specialists, public health workers, and academicians from Latin America. This publication includes summaries of 55 presentations that were given orally in Spanish or presented as posters by participants from 4 countries in Latin America and the USA. Topics addressed in the symposium included: surveillance, chemical and biological control, and insecticide resistance associated with Aedes aegypti; distribution, behavior, and control of Culex; bionomics, ecology, and chemical and biological control of Anopheles vectors of malaria; insecticide resistance; and studies of dengue, West Nile virus, and Triatoma spp.