Following the resurgence of malaria in India, which was partially the result of an increased incidence of urban cases, alternative control methods against the vectors in urban areas were examined and adopted. During the continued examination of new insecticides, pirimiphos-methyl was tested and shown to be effective as a larvicide when applied each week at a rate of 12.5g active ingredient/hectare. Anti-larval operations with this treatment carried out in the urban areas of one large town resulted in a reduction of the incidence among children, and decreasing the Plasmodium falciparum infection.