1,5-Diphenyl-1,2,4-triazole-3-carboxylic acid derivatives of formula ##STR1## wherein each of R.sub.a and R.sub.b, independently of the other, is halogen, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 haloalkyl, C.sub.2 -C.sub.5 alkenyl, C.sub.2 -C.sub.5 alkynyl or cyano, n is zero or a number from 1 to 3 and OR is hydroxy, a phytophysiologically tolerable metal or ammonium salt radical, or an ester radical defined in the description, are capable of specifically antagonizing the phytotoxic action of herbicides.1,5-Diphenyl-1,2,4-triazole-3-carboxylic acid derivatives of formula I and the preparation thereof, compositions containing these components as selective herbicides and the use of these two active ingredient components for controlling weeds in crops of useful plants are described.