Susceptibility to some WHO-approved public health insecticides by female Anopheles gambiae sensu lato (malaria vector) and the efficiency of piperonyl butoxide (PBO)-bednet insecticides was tested in fresh water swamp vegetation of Rivers State, Nigeria. Larval samples using standard dipping technique were collected in rainy season. Technical grade insecticides used in the bioassay comprised of Pyrethroids (Permethrin, Deltamethrin, Lambda-cyhalothrin, Alpha-cypermethrin), Carbamates (Bendiocarb, Propoxur), Organochlorine (Dichlorodiphenyltrichloroethane) and Organophosphate (Primiphos-methyl). 25 non-bloodfed adults, three to five days old were introduced into each of the four-replicate and control bottles. Number of dead mosquitoes at 15, 30, 35, 40, 45, 60, 75, 90, 105, 120 minutes, was noted. PBO synergist test with deltamethrin and permethrin was done. ANOVA examined the differences in vector mortality. Percentage mortality of the vector to: bendiocarb-99 and alpha-cypermethrin-100, agreed with WHO recommendations. There was partial recovery of susceptibility with PBO- (permethrin and deltamethrin). Bendiocarb and alpha-cypermethrin are effective for indoor residual spraying (IRS). Recovery of susceptibility by PBO-pyrethroids gives them edge over lone pyrethroids, and they are recommended for impregnation of long-lasting insecticidal nets (LLINs).