Abstract: A process for manufacturing a pre-impregnated fibrous material, including a step of impregnation of said fibrous material with a matrix being of a thermoplastic polymer in the molten state. This process is characterized in that, prior to the impregnation step, an insertion step of incorporating, into said impregnating thermoplastic polymer, a lubricant including at least one oligomer chosen from oligomers of a cyclic ester, oligomers of a cyclic ether and oligomers of an organomineral compound. This oligomer makes it possible to lubricate the thermoplastic polymer, to promote wetting of the fibres of the fibrous material, and therefore to notably improve the impregnation of the fibrous material.