Single-wall carbon nanotube (SWCNT) buckypaper/epoxy composites were prepared and their electromagnetic interference (EMI) shielding was investigated. The EMI shielding increased with the thickness of the SWCNT buckypaper. The buckypaper is a large-area freestanding preform that can be easily infiltrated by epoxy, without the dispersion problem associated with a powder conductive filler. At a low content of SWCNTs, the composite exhibited relatively high EMI shielding in the low frequency region.