Bearing structure (1; 50) for passenger and/or driver seats of vehicles, comprising: - at least one substantially L-shaped support body (2; 51) in order to comprise a base portion adapted to support the seating of a passenger and/or driver seat, and an upwardly protruding abutting portion adapted to support the backrest of said passenger and/or driver seat, at least one between said base portion and said abutting portion being provided with a pair of folded side edges (6, 7) opposite to each other, outwardly protruding according to a plane substantially orthogonal to the plane defined by a bottom central wall of said base portion and/or of said abutting portion, on said folded side edges (6,7) being formed a double S-shaped fold defining an abrupt offset in order to define a first section of the folded edge, developing parallel to a plane defined by each of said side edges (6, 7); - reinforcement means (8; 57) transversally coupled to said support body (2;51) substantially in proximity of or at a junction zone connecting said base portion to said abutting portion, characterized by the fact that said base portion and said abutting portion partially overlap said reinforcement means (8; 57) at a respective overlapping zone (14; 15) and at least one longitudinal section (6a, 7a) of at least one of said side edges (6, 7) comprises: - a first auxiliary bend defining a plane substantially orthogonal to said plane defined by each of said folded side edges (6, 7); - a second auxiliary bend consecutive to said first auxiliary bend, and disposed at the free end (61a, 71a) of at least one of said side edges (6, 7) and defining a plane substantially orthogonal to said plane defined by said first auxiliary bend and substantially parallel to the plane defined by each of said folded side edges (6, 7), so that at least one of said side edges (6, 7) is folded for at least said longitudinal section (6a, 7a) according to a profile which, in a transversal cross-section, has a hook shape. - at least one substantially L-shaped support body (2; 51) in order to comprise a base portion adapted to support the seating of a passenger and/or driver seat, and an upwardly protruding abutting portion adapted to support the backrest of said passenger and/or driver seat, at least one between said base portion and said abutting portion being provided with a pair of folded side edges (6, 7) opposite to each other, outwardly protruding according to a plane substantially orthogonal to the plane defined by a bottom central wall of said base portion and/or of said abutting portion, on said folded side edges (6,7) being formed a double S-shaped fold defining an abrupt offset in order to define a first section of the folded edge, developing parallel to a plane defined by each of said side edges (6, 7); - reinforcement means (8; 57) transversally coupled to said support body (2;51) substantially in proximity of or at a junction zone connecting said base portion to said abutting portion, characterized by the fact that said base portion and said abutting portion partially overlap said reinforcement means (8; 57) at a respective overlapping zone (14; 15) and at least one longitudinal section (6a, 7a) of at least one of said side edges (6, 7) comprises: - a first auxiliary bend defining a plane substantially orthogonal to said plane defined by each of said folded side edges (6, 7); - a second auxiliary bend consecutive to said first auxiliary bend, and disposed at the free end (61a, 71a) of at least one of said side edges (6, 7) and defining a plane substantially orthogonal to said plane defined by said first auxiliary bend and substantially parallel to the plane defined by each of said folded side edges (6, 7), - a first auxiliary bend defining a plane substantially orthogonal to said plane defined by each of said folded side edges (6, 7); - a second auxiliary bend consecutive to said first auxiliary bend, and disposed at the free end (61a, 71a) of at least one of said side edges (6, 7) and defining a plane substantially orthogonal to said plane defined by said first auxiliary bend and substantially parallel to the plane defined by each of said folded side edges (6, 7),