Methods followed and results obtained in the 1942 mosquito survey at Camp Crowder, Mo., are discussed. In 280 collections of immature mosquitos, 108 hand collections of adults, and 167 light trap collections, 31 spp. were collected, 26 from larval habitats. The most prevalent spp. were Anopheles punctipennis, Culex pipiens, C. restuans, Aedes vexans, and Psorophora columbiae Anopheles quadrimaculatus was generally distributed in the area but was found nowhere in large numbers. Immature mosquitos were most commonly found in puddles and small temporary pools, natural holes in trees and stumps, small, spring-fed streams, ditches, and barrels, cans, and other artificial receptacles.