In an area of India where the main rural malaria vector, Anopheles culicifacies Giles, has developed triple resistance to DDT, HCH, and malathion sprayed indoors in antimalaria program, bifenthrin (10% wettable powder) was evaluated in a randomized house-scale trial between July 1999 and March 2000. Entomological impact of four serial doses of bifenthrin (25, 50, 100, and 200 mg/m²) sprayed in rooms in five villages was compared with malathion (2 g/m²) and unsprayed control. An. culicifacies was 100% susceptible to bifenthrin (0.1%), but only 57% to malathion (5%) test papers. Contact bioassays were carried out on sprayed surfaces for 24 wk, and 24 h mortality in An. culicifacies was recorded. Bifenthrin 100- and 200-mg doses caused ≥80% mortality until 24 wk. The 50-mg dose caused ≥80% mortality on tin, wood, and mud surfaces for 24 wk, and on brick walls for 16 wk. Bifenthrin 25-mg dose produced ≥80% mortality for 24 wk on tin, 20 wk on mud walls, 16 wk on brick walls, and 8 wk on wood surfaces. Persistence of ≥80% mortality did not differ for 25- and 50-mg doses on any surface except on wood (P < 0.05). Malathion sprayed in three rounds of 6 wk apart caused ≥80% mortality for 16 wk on the brick and mud walls, and for 20 wk on the tin and wood surfaces. Bifenthrin 25- and 50-mg doses produced a similar impact on the densities of An. culicifacies and other mosquitoes but a superior one to malathion or control. Bifenthrin 25-mg dose caused least excito-repellency. Overall, efficacy of bifenthrin was superior to malathion. Considering the duration of the persistence of significant insecticidal action of bifenthrin on the most common surfaces (mud and brick walls), least excito-repellency and a relative impact on the mosquito densities, the 25-mg dose was the most superior among all the four doses evaluated.