Studies on the susceptibility of Anopheles gambiae to insecticides were carried out in rice field areas of Côte-d'Ivoire. An. gambiae larvae populations from Côte-d'Ivoire were resistant to DDT but susceptible to organophosphorous insecticides. Adult populations from the surroundings of Bouake were resistant to DDT and permethrin. Resistance to propoxur was strongly suspected. The knock-down effect of both deltamethrin and lambdacyhalothrin was delayed and strongly decreased. The control strain from Bobo-Dioulasso and populations from rice fields of Katiola located far from the city were still susceptible to the three pyrethroids. It is likely that resistance to pyrethroids in Bouake has been promoted by the intensive use of domestic aerosol sprays.