Discontinuous nickel filaments of diameter 0.4 mu m and having a carbon core of diameter 0.1 mu m were fabricated by electroplating nickel on discontinuous carbon filaments. They exhibited a grain size of 0.016 mu m and electrical resistivity of about 5 x 10(-6) Omega.cm. In an amount as low as 7 vol.% in a polymer (polyether sulfone) matrix, they resulted in a composite exhibiting electromagnetic interference shielding effectiveness of 87 dB and reflection coefficient 0.95 at 1-2 GHz, tensile strength 52 MPa, tensile ductility 1.0%, and density 1.87 g/cm(3).