The Medical Entomology Section -of the Department of Health has previously conducted a survey of potential areas of mosquito activity in the Darwin East area. The earlier survey in 1974-75 was of a more extensive nature to delineate areas of extensive mosquito breeding and to establish the species of vector and pest mosquitoes in the area. The recognition of extensive areas of mosquito breeding in the northern coastal swamps contributed to the concept of limiting urban development to the southern section of the acquisition area. The present survey was undertaken to make a more intensive investigation in the southern area to establish the major breeding sites and to advocate specific engineering requirements that would reduce the biting insect contact with future residents.