Method for controlling the quality of a tyre for vehicle wheels comprising: - locating a position reference in a marking on a sidewall of said tyre; - inspecting said tyre to search for production defects; - determining the position of each detected production defect with respect to said position reference; characterized in that said marking comprises a specific mark that either: - consists of a first radial line, a second radial line and a third radial line, wherein said first radial line and said third radial line are positioned, respectively, at the two sides of the second radial line, are symmetrical to one another with respect to said second radial line, and are radial lines with a shorter length L L than the length L C of the second radial line, each of said first radial line, second radial line and third radial line being arranged on a plane comprising the rotation axis of the tyre; or - comprises a first line, a second radial line and a third line, said first line and said third line being positioned, respectively, at the two sides of the second radial line and being symmetrical to one another with respect to said second radial line, wherein said first line and said third line are open polygonal chains, or open curved lines; or - comprises a plurality of first radial lines (53 i) at one side of a second radial line and a plurality of third radial lines (52 i) at another side of the second radial line, and wherein the plurality of first radial lines (53 i) and the plurality of third radial lines (52 i) are symmetrical to one another with respect to said second radial line and have a shorter length than the length of the second radial line, the length of the plurality of first and third radial lines increasing going away from the second radial line, and in that locating said position reference comprises: - identifying said specific mark by detecting said first line or said plurality of first radial lines (53 i), said second radial line and said third line or said plurality of third radial lines (52 i), - said second radial line defining the position reference. - locating a position reference in a marking on a sidewall of said tyre; - inspecting said tyre to search for production defects; - determining the position of each detected production defect with respect to said position reference; - consists of a first radial line, a second radial line and a third radial line, wherein said first radial line and said third radial line are positioned, respectively, at the two sides of the second radial line, are symmetrical to one another with respect to said second radial line, and are radial lines with a shorter length L L than the length L C of the second radial line, each of said first radial line, second radial line and third radial line being arranged on a plane comprising the rotation axis of the tyre; or - comprises a first line, a second radial line and a third line, said first line and said third line being positioned, respectively, at the two sides of the second radial line and being symmetrical to one another with respect to said second radial line, wherein said first line and said third line are open polygonal chains, or open curved lines; or - comprises a plurality of first radial lines (53 i) at one side of a second radial line and a plurality of third radial lines (52 i) at another side of the second radial line, and wherein the plurality of first radial lines (53 i) and the plurality of third radial lines (52 i) are symmetrical to one another with respect to said second radial line and have a shorter length than the length of the second radial line, the length of the plurality of first and third radial lines increasing going away from the second radial line, - identifying said specific mark by detecting said first line or said plurality of first radial lines (53 i), said second radial line and said third line or said plurality of third radial lines (52 i), - said second radial line defining the position reference.