The present invention relates to a motor vehicle rear floor (32) that is intended to form part of a motor vehicle rear block, the block including two longitudinal rails (12), each having a front end forming a rear structural node (20) of the vehicle and a rear end (14), the rear ends being arranged to serve as bearing points for an impact beam (15). The floor further includes reinforcement (22) having at least one rear end (24) arranged to serve as a bearing point for the impact beam (15), and two limbs (22a, 22b) each intended to extend in a straight line from the rear end (24) of the reinforcement to one of the nodes (20).