The present invention provides fungicidal 4-substituted-3-{phenyl[(heterocyclylmethoxy)imino]methyl}-1,2, 4-oxadiazol-5(4H)-one derivatives of formula (I) wherein A represents a pyridyl or thiazole group and X1, Y1 to Y5 represent independently different substituents.La presente invención proporciona derivados de 3-{fenil[(heterociclilmetoxi)imino]metil}-1,2,4-oxadiazol-5(4H)-o na sustituidos en 4 de fórmula (I) (ver Fórmula) en donde A representa un grupo piridilo o tiazol y X1, Y1 a Y5 representan independientemente diferentes sustituyentes.