6-(2-Trifluoromethyl-phenyl)-triazolopyrimidines of formula I in which R1 and R2 independently denote hydrogen or alkyl, alkenyl, alkynyl, alkadienyl, or haloalkyl, cycloalkyl, bicycloalkyl, phenyl, naphthyl, or 5- or 6-membered heterocyclyl, containing one to four nitrogen atoms or one to three nitrogen atoms and one sulfur or oxygen atom, or 5- or 6-membered heteroaryl, containing one to four nitrogen atoms or one to three nitrogen atoms and one sulfur or oxygen atom, or where R1 and R2 radicals may be unsubstituted or substituted as defined in the specification; or R1 and R2 together with the interjacent nitrogen atom represents a 5- or 6-membered heterocyclic ring, containing one to four nitrogen atoms or one to three nitrogen atoms and one sulfur or oxygen atom, which may be substituted as defined in the specification; R3 is hydrogen, halogen, alkyl, alkoxy and haloalkyl; and X is halogen; processes and intermediates for preparing these compounds, compositions comprising them and their use for controlling phytopathogenic fungi are described.