The effects of 2 growth regulators, diflubenzuron (DFB) and OMS 2017, on the ability of females Aedes aegypti to become infected with Molinema dessetae was studied under laboratory conditions. OMS 2017 and DFB had no effect on either the amount of blood ingested or the microfilarial load. The infective potential of females that survived DFB treatment was significantly greater than untreated females, but there was no difference between OMS 2017-treated and control females. The percentage of infective larvae in the head after OMS 2017 and DFB treatments was significantly greater than for control females. Insect growth regulators appear to affect the vectorial competence of mosquitoes, and these results indicate the need for preliminary studies before these compounds are used in large-scale control programs.