The invention relates to fungicidal N-cycloalkyl-N-{[ortho-(1-substituted-cycloalkyl)heteroaryl]methyl}carboxamides and their thiocarbonyl analogs of formula (I), their process of preparation, their use as fungicides, particularly in the form of fungicidal compositions, and methods for the control of phytopathogenic fungi of plants using these compounds or their compositions. A represents a carbo-linked, unsaturated or partially saturated, optionally substituted 5-membered heterocyclyl group; T represents O or S; Z1 represents an optionally substituted C3-C7-cycloalkyl; p represents 1-5; B1 represents a carbo-linked, unsaturated, monocyclic or fused bicyclic 5-, 6-, 8-, 9-, 10-membered heterocyclyl ring, wherein the dotted line between the two adjacent carbons represents a single bond, a double bond or an aromatic bond.