The susceptibility of Fijian Aedes pseudoscutellaris and Ae. Polynesiensis to infection with the Mermithid nematode, Romanomermis culicivorax, was assessed under controlled laboratory conditions. Both mosquito species were equally susceptible to infection. Infection rates in fourth instar larvae, following exposure to infection as first instars, ranged from 88% to 96% at a treatment ratio (worms:mosquito) of 5:1. Infection rates were 98% in Ae. polynesiensis and 100% in Ae. pseudoscutellaris at a treatment ration of 10:1, and 100% in both species at ratio of 20:1. These are the first data available on the susceptibility of Ae. pseudoscutellaris to infection by R. culicivorax. Data presented could provide a baseline for determining dosage rates for field trails should attempts be made to control these mosquitoes with R. culicivorax.