For nine weeks from 14 April to 13 June 1975 an average of over 500 double translocation heterozygote male Aedes aegypti (L.) were released daily into a village where the estimated adult mosquito population was 1200. The two purposes of this release were to suppress the A. aegypti population by sterility induced by chromosomal translocations and to assess the effect of rainy season conditions on the population dynamics of the indigenous and released mosquitoes. As a result of the releases, hatchabirity of eggs from females collected during landing-biting catches dropped from over 93% to 30–40%. For eight weeks following the termination of the releases, hatchability remained below 70% while that of the reference village averaged between 80 and 99% hatch. A relative population decline observed in the release village is not attributed solely to the effect of the releases, partly because it occurred before sufficient time had elapsed to allow induced sterility to build up in the field population.