Abstract: A method for manufacturing a T-shaped composite part by resin transfer molding, includes the following steps: making a preform with a planar stack of plies and with two L-shaped stacks of plies; placing the preform so that the L-shaped stacks meet between two cores of a resin transfer molding tool; inserting and removing fibers through the planar stack in a direction perpendicular or quasi-perpendicular to the planar stack and so that loops are formed inside a portion of the L-shaped stacks which are substantially perpendicular to the planar stack; closing the resin transfer molding tool; injecting a resin into the resin transfer molding tool; and heating the resin transfer molding tool to cure the resin.