Novel pyraole derivatives of formula (I), wherein: X is oxygen or sufu, R.sub.1 is C.sub.1 C.sub.3alkyl, C.sub.1 C.sub.3haloalkyl, C.sub.1 C.sub.3alkoxy-C.sub.1 C.sub.3alkyl or C.sub.1 C.sub.3haloalkoxy-C.sub.1 C.sub.3alkyl; R.sub.2 is C.sub.1 C.sub.3haloalkyl; and R.sub.3 is halogen. The novel compounds have plant-protective properties and are suitable for protecting plants against infestations by phytopathogenic microorganisms.