The electrical conductivity of composites of exfoliated graphite nanoplatelets (GNPs), including bromine-doped GNP, and conjugated polyacrylonitrile has been investigated. The focal point is the dual nature of the graphite nanoparticles, which exhibit both intrinsic electrical conductivity and doping capability of semiconductive polymers such as conjugated polyacrylonitrile to form charge-transfer complexes. The conductivity is particularly enhanced in conjugated polyacrylonitrile composites (e.g., with 6 wt.-% graphite nanoplatelets) where the value rises from 1 x 10-" to 2 x 10-' S -cm-', which reflects jointly the conductivity of the doped semi-conductive polymer together with the percolation-based conduc- A tivity of the particles.