A support for motor-vehicle doors, in particular adapted for installation on a mobile assembly station for motor vehicles, comprising: - a column member having a longitudinal axis; and - a support unit configured for receiving at least one motor-vehicle door and including a slider coupled to said column member and axially movable along said longitudinal axis, said support unit comprising at least one first articulated member (8, 10) connected to said slider, wherein a first portion (8A, 10A) of said articulated member (8, 10) is fixed to the slider and a second portion (8B, 10B) of said articulated member (8, 10) is pivotally connected to said first portion (8A, 10A) and carries at least one receiving element for a motor-vehicle door, and wherein the second portion (8B, 10B) of each articulated member (8, 10) is movable with respect to the first portion (8A, 10A) between a collapsed position and a deployed position, where in the deployed position a distance between the second portion (8B, 10B) and the first portion (8A, 10A) is greater than the distance between the second portion (8B, 10B) and the first portion (8A, 10A) in the collapsed position, the support being characterized in that it further includes a second articulated member connected to said slider, said second articulated member including a respective first portion fixed to the slider and a respective second portion pivotally connected to said first portion and carrying at least one receiving element for a motor-vehicle door, wherein the second portion of said second articulated member is movable with respect to the first portion between a collapsed position and a deployed position, wherein in the deployed position a distance between the second portion and the first portion is greater than the distance between the second portion and the first portion in the collapsed position. - a column member having a longitudinal axis; and - a support unit configured for receiving at least one motor-vehicle door and including a slider coupled to said column member and axially movable along said longitudinal axis, said support unit comprising at least one first articulated member (8, 10) connected to said slider, wherein a first portion (8A, 10A) of said articulated member (8, 10) is fixed to the slider and a second portion (8B, 10B) of said articulated member (8, 10) is pivotally connected to said first portion (8A, 10A) and carries at least one receiving element for a motor-vehicle door, and wherein the second portion (8B, 10B) of each articulated member (8, 10) is movable with respect to the first portion (8A, 10A) between a collapsed position and a deployed position, where in the deployed position a distance between the second portion (8B, 10B) and the first portion (8A, 10A) is greater than the distance between the second portion (8B, 10B) and the first portion (8A, 10A) in the collapsed position, the support being characterized in that it further includes a second articulated member connected to said slider, said second articulated member including a respective first portion fixed to the slider and a respective second portion pivotally connected to said first portion and carrying at least one receiving element for a motor-vehicle door, wherein the second portion of said second articulated member is movable with respect to the first portion between a collapsed position and a deployed position, wherein in the deployed position a distance between the second portion and the first portion is greater than the distance between the second portion and the first portion in the collapsed position.