A pest control composition and a pest control method which have the heightened effect of controlling harmful insects living in soils and/or seeds and simultaneously have the heightened effect of controlling diseases infectious through soils and/or seeds. The pest control composition contains as active ingredients at least one organophosphorus compound selected from the group consisting of S-sec-butyl O-ethyl 2-oxo-1,3-thiazolidin-3-ylphosphonothioate, O-ethyl-S-n-propyl(2-cyanoimino-3-ethylimidazolidin-1-yl)-phosphonothiolates, and S,S-di-sec-butyl O-ethyl phosphorodithioate and at least one bactericide selected from the group consisting of fluazinam, benomyl, tolclophos-methyl, metalaxyl, captan, iprodione, chlorothalonil, dazomet, hymexazol, flutolanil, and validamycin. The method comprises using the composition.
