Thin graphite nanoplatelets synthesized by an intercalation/exfoliation process are incorporated into a polymer fiber matrix by an electrospinning process, creating ultrafine nanocomposite fibrils (see Figure). Uniform nanofibers of average diameter 300 nm show a modest increase in thermal stability with increasing weight percentage of graphite nanoplatelets. The mechanical properties of the fibrils are examined, and the normalized Young's modulus is found to increase two-fold upon addition of 4 wt.-% graphite nanoplatelets.