We report a new technique to enhance the electrical conductivity of transparent single-walled carbon nanotube (SWNT) films with a negligible loss of their optical transmittance. Hybridization of the SWNT films with gold nanoparticles increased the electrical conductivity 2-fold to a maximum of 2.0 x 10(5) S/m while maintaining the transmittance of the initial value. The same trends are shown for other SWNT films with various initial conductivities and transparency levels. Functional changes in the gold-nanoparticle-coated SWNT films suggest that the electrical conductivity change is due to an electron depletion mechanism as a result of a doping effect.