The mosquito larval and pupal fauna of a dambo in a primary forest in Nairobi Area, Kenya was monitored during the short rainy season. The density of the immature stages of 6 species was recorded daily for a 3 month period. Aedes cumminsii mediopunctatus, Ae. lineatopennis and Ae. sudanesis were the first 3 species collected following flooding. Culex quasiguiarti, Anopheles coustani and Cx. theileri were collected beginning 15,17 and 33 days respectively following flooding. Each of the 3 Aedes spp. disappeared after on generation. No immature mosquitoes were recovered after day 48.