The present invention provides an insecticidal composition comprising, as active ingredients, (a) at least one pyrethroid compound and (b) an N-arylpyrazole compound such as 5-amino-3-cyano-1-(2,6-dichloro)-4-trifluoromethylphenyl)-4-trifluoromethy lsulfinylpyrazole, and an insecticidal method which comprises applying the composition.