A method for automatically measuring linear dimensions of manufactured objects of a series consisting in: - selecting a series of manufactured objects in which each of said objects is made of a material with a constant attenuation coefficient at all points of the object; - selecting at least one region to be inspected from the objects in which at least one linear dimension is to be measured; - transporting, by means of a transport device, the moving objects in a displacement direction along a substantially rectilinear trajectory in a conveying plane ( Pc), these objects generating a conveying volume ( Vt) during their displacement; - positioning, outside the conveying volume ( Vt), at least one focus ( Fj) of an X-ray generator tube and image sensors ( Cji) each exposed and sensitive to X-rays obtained from an associated focus ( Fj), these X-rays having passed through at least the region to be inspected producing on each image sensor a radiographic projection in the direction of projection ( Dji); - acquiring using image sensors ( Cji), for each object during its displacement, at least three radiographic images of the region to be inspected, obtained from at least three radiographic projections of the region to be inspected, the directions of projection ( Dji) of which are different from each other; - analyzing the at least three radiographic images, using a computer system; - providing the computer system with an a priori geometric model of the region to be inspected for the series of objects; - determining using the computer system by considering a constant attenuation coefficient and from the a priori geometric model and at least three radiographic images of the region to be inspected, a digital geometric model of the region to be inspected for each object of the series consisting of at least two three-dimensional points each belonging to a border surface of the region to be inspected and located in a plane not orthogonal to a direction of projection Dji; - for each object of the series, determining from the digital geometric model of the region to be inspected, at least one linear dimension measurement of the region to be inspected as the distance between at least two three-dimensional points each belonging to a border surface of the region to be inspected and located in a plane not orthogonal to a direction of projection ( Dji). - selecting a series of manufactured objects in which each of said objects is made of a material with a constant attenuation coefficient at all points of the object; - selecting at least one region to be inspected from the objects in which at least one linear dimension is to be measured; - transporting, by means of a transport device, the moving objects in a displacement direction along a substantially rectilinear trajectory in a conveying plane ( Pc), these objects generating a conveying volume ( Vt) during their displacement; - positioning, outside the conveying volume ( Vt), at least one focus ( Fj) of an X-ray generator tube and image sensors ( Cji) each exposed and sensitive to X-rays obtained from an associated focus ( Fj), these X-rays having passed through at least the region to be inspected producing on each image sensor a radiographic projection in the direction of projection ( Dji); - acquiring using image sensors ( Cji), for each object during its displacement, at least three radiographic images of the region to be inspected, obtained from at least three radiographic projections of the region to be inspected, the directions of projection ( Dji) of which are different from each other; - analyzing the at least three radiographic images, using a computer system; - providing the computer system with an a priori geometric model of the region to be inspected for the series of objects; - determining using the computer system by considering a constant attenuation coefficient and from the a priori geometric model and at least three radiographic images of the region to be inspected, a digital geometric model of the region to be inspected for each object of the series consisting of at least two three-dimensional points each belonging to a border surface of the region to be inspected and located in a plane not orthogonal to a direction of projection Dji; - for each object of the series, determining from the digital geometric model of the region to be inspected, at least one linear dimension measurement of the region to be inspected as the distance between at least two three-dimensional points each belonging to a border surface of the region to be inspected and located in a plane not orthogonal to a direction of projection ( Dji).