The present invention relates to 2,5-disubstituted-4-pyrimidinyl-substituted-phenyl-amidine derivatives of formula (I) in which the substituents are as in the description, notably to 2,5-dialkyl-4-pyrimidinyl-substituted-phenyl-amidine derivatives, their process of preparation, their use as fungicide or insecticide active agents, particularly in the form of fungicide or insecticide compositions, and methods for the control of phytopathogenic fungi or damaging insects, notably of plants, using these compounds or compositions. ##STR00001##