The invention relates to a method of manufacturing a single-piece hollow fan blade for turbine engines comprising a foot (2) extended by a rotor blade (4) in a radial direction, the method comprising the following stages: making via forging of a single-piece fan blade (1) with a plurality of inserts; and eliminating of the inserts so as to obtain a plurality of recesses (16) in this blade. The invention also relates to such a blade (1) fitted with a plurality of recesses (16) each extending substantially and radially along a curved central line (18).