The electromagnetic observability of epoxy-matrix composites containing continuous carbon fibers was decreased by using epoxy-coated carbon fibers. The attenuation of electromagnetic waves at 1.0-1.5 GHz upon reflection was increased from 1.3 to 1.7 dB, while the attenuation upon transmission was decreased from 30 to 24 dB. The effect is attributed to the decreased transverse electrical conductivity of the composite due to the epoxy coating. The epoxy coating caused the tensile strength and modulus of the composite to decrease by about 10%, while the elongation at break was not affected.