Abstract: A mannequin for supporting a pair of trousers whereon a laser marking is performed, having two leg structures housed inside the trouser legs. Each structure has a longitudinal axis, upper and lower areas, front and rear planes, an inner side and outer side. The separation between the inner and outer sides varies due to the tensing mechanism in order to go from a non-operative loosened position (A) to a maximum tensed end position (B) to perform the marking. Each leg structure is coupled to a respective main rotation axis around which rotates by a respective articulation having the mannequin for each leg structure. The main rotation axis is parallel to the direction of the dimension of the rise of the pair of trousers or collinear with it. The front planes can form at least two angles greater and/or less than 180° when rotated around the respective main rotation axes thereof.