A survey of Anopheles pseudopunctipennis larval habitats was performed throughout most of its known geographic range. Eleven key environment variables characterized most larval habitats of this important vector of malaria in the Americas. Larval habitats occurred mainly in valley and foothill areas which were often situated in arid regions. Immatures were found primarily during the dry season in sun-exposed freshwater stream pools with clear, shallow, stagnant water containing abundant filamentous green algae and/or aquatic vegetation.