A process for producing guides for lifts or similar products, comprising the following steps: - providing a raw guide; - preferably applying a torsional stress to the guide for removing a twist by a twisting apparatus; - carrying out at least one straightening operation by a straightening apparatus; - carrying out finish operations on the guide; the straightening operation comprises the following sub-steps: - supporting said guide by a supporting frame; - providing at least two reading units (10, 11) acting on respective lateral grip areas (13a, 13c) of the guide; - providing at least one work unit presenting an inverted-"C" configuration and acting on a central grip area of the guide, said work unit being configured to engage an upper region of the guide to apply a force on the guide by a pulling or pushing action, the reading units being disposed laterally of the work unit placed in the middle along an ideal extension axis of the guide; - reading, through the reading units (10, 11) and through the working unit, respective positions (P, P', P") of the lateral grip areas (13a, 13c) and of the central grip area relative to the ideal longitudinal extension axis of the guide; - determining, by a control unit, an appropriate command signal to be sent to the work unit for establishing the work position and in particular the deformation condition imposed to the guide for displacement of the grip area relative to the lateral grip areas (13a, 13c), according to said reading of respective positions (P, P', P"); - applying a force transverse to the ideal longitudinal extension axis by said work unit according to said command signal, the transverse force being applied in the position (P') of the central grip area, the transverse force being a function at least of the operation of reading the positions (P, P', P") of the lateral grip areas (13a, 13c) and the position (P') of the central grip area to bring a real longitudinal extension of the guide to a condition of substantial alignment with the ideal longitudinal extension axis; characterised in that it comprises also the step of determining, by a correction module, a correction factor of the theoretical work position corresponding to the theoretical deformation condition to be imposed to the guide for displacement of the central grip area and the condition of substantial longitudinal alignment, said determination of the correction factor of the theoretical work position and said determination of the condition of substantial longitudinal alignment being carried out preferably by a software module and correcting the work position as a function of the real deformation occurred and read during the working step on the preceding central grip areas of the guide itself. - providing a raw guide; - preferably applying a torsional stress to the guide for removing a twist by a twisting apparatus; - carrying out at least one straightening operation by a straightening apparatus; - carrying out finish operations on the guide; the straightening operation comprises the following sub-steps: - supporting said guide by a supporting frame; - providing at least two reading units (10, 11) acting on respective lateral grip areas (13a, 13c) of the guide; - providing at least one work unit presenting an inverted-"C" configuration and acting on a central grip area of the guide, said work unit being configured to engage an upper region of the guide to apply a force on the guide by a pulling or pushing action, the reading units being disposed laterally of the work unit placed in the middle along an ideal extension axis of the guide; - reading, through the reading units (10, 11) and through the working unit, respective positions (P, P', P") of the lateral grip areas (13a, 13c) and of the central grip area relative to the ideal longitudinal extension axis of the guide; - determining, by a control unit, an appropriate command signal to be sent to the work unit for establishing the work position and in particular the deformation condition imposed to the guide for displacement of the grip area relative to the lateral grip areas (13a, 13c), according to said reading of respective positions (P, P', P"); - applying a force transverse to the ideal longitudinal extension axis by said work unit according to said command signal, the transverse force being applied in the position (P') of the central grip area, the transverse force being a function at least of the operation of reading the positions (P, P', P") of the lateral grip areas (13a, 13c) and the position (P') of the central grip area to bring a real longitudinal extension of the guide to a condition of substantial alignment with the ideal longitudinal extension axis; characterised in that it comprises also the step of determining, by a correction module, a correction factor of the theoretical work position corresponding to the theoretical deformation condition to be imposed to the guide for displacement of the central grip area and the condition of substantial longitudinal alignment, said determination of the correction factor of the theoretical work position and said determination of the condition of substantial longitudinal alignment being carried out preferably by a software module and correcting the work position as a function of the real deformation occurred and read during the working step on the preceding central grip areas of the guide itself.