The present invention relates to novel fungicidal two-component compositions based on metalaxyl having an R-enantiomer content of more than 70% by weight as one essential component and a second fungicidal component, for the treatment of phytopathogenic diseases of crop plants, especially phytopathogenic fungi, and to a method of combating phytopathogenic diseases on crop plants. The metalaxyl component is called active ingredient I.The following fungicides may be used as the second component II of the mixture: either a compound IIA N-(3'-(1'-chloro-3-methyl 2'-oxopentan))-3,5-dichloro-4-methylbenzamide (EP-600629); or a compound IIB (EP-253213) methyl (E)-2-methoxyimino-[2-(o-tolyloxymethyl)phenyl]acetate; or a (S)-valinamide of formula IIC (EP-472996) ##STR00001## wherein R.sub.4 is isopropyl, and R.sub.5 is 4-methylphenyl, and wherein the asymmetric center is preferably (R); or a compound IID (EP-551048) (S)-1-anilino-4-methyl-2-methylthio-4-phenylimidazolin-5-one; or a compound IIE, the Pseudomonas fluoresens strain, ATCC accession No. 55169 (U.S. Pat. No. 5,348,742) is particulary effective in combating or preventing fungal diseases of crop plants. These combinations exhibit synergistic fungicidal activity.