Permethrin (125 mg m2) and fenitrothion (2000 mg m2 ) as wettable powders and NRDC 161 (15 mg2) as an emulsifiable concentrate or suspension concentrate were applied as deposits on interior surfaces of houses in a village in Kenya to control endophilic mosquitoes. Mosquito populations and behavior were assessed during pyrethrum spray counts, exit traps, human bait catches and light traps. Permethrin and NRDC 161 formulations reduced the number of Anopheline mosquitoes resting in houses. The reduction was at least as effective as in fenitrothion-treated houses over the 24 wk post-treatment assessment period. The results bear out previous work that indicates that reduction in pyrethroid treated houses is at least partly a repellent effect. Residual sprays of permethrin and NRDC 161 also reduced biting in houses by Mansonia spp.