Transmission of Plasmodium gallinaceum to chickens by adult mosquitoes eclosed from larvae that consumed infected adult mosquitoes was investigated. No malarial infections were observed in chicks fed on by mosquitoes that eclosed from larvae that had consumed crushed infected adult mosquitoes. Where cadavers with noncrushed thoraces were used, 3 of 4 chicks fed on by adult mosquitoes developed parasitemias ranging from 6 to 11% infected erythrocytes.