A method for repairing a part made of composite material comprising a fiber reinforcement having a three-dimensional weaving between a plurality of warp yarns and a plurality of weft yarns, said fiber reinforcement being densified by a matrix, said method comprises: - the identification of at least one damaged area in the part, - the production of a recessed section by removal of the composite material at the damaged area so as to form a recessed section extending from a first face of the composite material part to a second face of said part, - the production of a first plurality of grooves extending on the first face of the composite material part from the edge(s) (31, 32, 33, 34, 35) of the recessed section, - the production of a second plurality of grooves extending on the second face of the composite material part from the edge(s) of the recessed section, - the production of a plurality of orifices within the thickness of the composite material part, each orifice opening out both into a groove of the first plurality of grooves and into a groove of the second plurality grooves, - the tree-dimensional weaving of at least one filling part fiber preform comprising a central section having a shape corresponding to the shape of the recessed section and a plurality of fiber bundles (720, 740, 750, 770) extending from the central section, - the placement of the central section of said at least one filling part fiber preform in the free volume of the composite material part delimited by the recessed section of the part, - the placement of a first portion of the fiber bundles of said at least one preform in the grooves of the first plurality of grooves present on the first face of the part and in the orifices of the plurality of orifices such that the fiber bundles of the first portion of the fiber bundles of said at least one preform open out into the grooves of the second plurality of grooves, - the placement of a second portion of the fiber bundles of said at least one preform in the grooves of the second plurality of grooves present on the second face of the part and in the orifices of the plurality of orifices such that the fiber bundles of the second portion of fiber bundles of said at least one preform open out into the grooves of the first plurality of grooves, - the impregnation of said at least one fiber preform with a precursor resin of a matrix, - the transformation of the resin into a matrix in order to obtain a filling part made of composite material comprising a fiber reinforcement densified by a matrix, said filling part occupying the volume defined by the recessed section. - the identification of at least one damaged area in the part, - the production of a recessed section by removal of the composite material at the damaged area so as to form a recessed section extending from a first face of the composite material part to a second face of said part, - the production of a first plurality of grooves extending on the first face of the composite material part from the edge(s) (31, 32, 33, 34, 35) of the recessed section, - the production of a second plurality of grooves extending on the second face of the composite material part from the edge(s) of the recessed section, - the production of a plurality of orifices within the thickness of the composite material part, each orifice opening out both into a groove of the first plurality of grooves and into a groove of the second plurality grooves, - the tree-dimensional weaving of at least one filling part fiber preform comprising a central section having a shape corresponding to the shape of the recessed section and a plurality of fiber bundles (720, 740, 750, 770) extending from the central section, - the placement of the central section of said at least one filling part fiber preform in the free volume of the composite material part delimited by the recessed section of the part, - the placement of a first portion of the fiber bundles of said at least one preform in the grooves of the first plurality of grooves present on the first face of the part and in the orifices of the plurality of orifices such that the fiber bundles of the first portion of the fiber bundles of said at least one preform open out into the grooves of the second plurality of grooves, - the placement of a second portion of the fiber bundles of said at least one preform in the grooves of the second plurality of grooves present on the second face of the part and in the orifices of the plurality of orifices such that the fiber bundles of the second portion of fiber bundles of said at least one preform open out into the grooves of the first plurality of grooves, - the impregnation of said at least one fiber preform with a precursor resin of a matrix, - the transformation of the resin into a matrix in order to obtain a filling part made of composite material comprising a fiber reinforcement densified by a matrix, said filling part occupying the volume defined by the recessed section.