The invention relates to a synthetic material end for a DC electric cable. In the invention, the synthetic material end includes a composite insert that is placed between the inner insulator and the outer insulating sleeve of the cable, the insert generally being in the form of a sheath surrounding the inner insulator over a partially-stripped portion of the cable, and being made up of a resistive portion of high resistivity, and of a semi-conductive portion of lower resistivity, the interface between said resistive and semi-conductive portions forming a deflector, the end of the resistive portion that is remote from the deflector being electrically connected to the central conductor of the cable, and the end of the semi-conductive portion that is remote from the deflector being electrically connected to the outer semi-conductor of the cable. Application to making connections to high-voltage electric cables.