The invention relates to a vehicle body structure having a body reinforcement behind the second row of seats, the body reinforcement including a beam assembly which is formed from two opposite longitudinal side beams (9, 10), a floor crossbeam (4) and two vertical side beams (5, 6), of which in each case a left-side longitudinal side beam (9), an associated end of the floor crossbeam (4) and a left-side vertical side beam (5) are connected at a left-side nodal point (11) and, correspondingly, the second longitudinal side beam (10) is connected to the other end of the floor crossbeam (4) and the second vertical side beam (10) at a right-side nodal point, and, at the two nodal points, corner reinforcements being fitted for increased stiffening in the transverse plane of the floor crossbeam (4) and the vertical side beams (5, 6). According to the invention, the longitudinal side beams (9, 10) are cast aluminum longitudinal side beams, on which in each case at the nodal point (11) a corner reinforcement is formed and integrated as an corner reinforcing profile (13) made of uniform material and projecting in the manner of a box, wherein the associated vertical side beam (5, 6) is connected to the corner reinforcing profile (13) at the top on one hand, and is connected to the floor crossbeam (4) laterally on the other hand.