The conductivity and dielectric constant of solutions of bitumen in toluene were determined for bitumens of differing asphaltene content. The results show that the conductivity is primarily controlled by the asphaltene content while the dielectric constant can be described in terms of the polarity and concentration of the various fractions of the bitumen. It is demonstrated that it is possible to determine bitumen content of a solution of bitumen in toluene by measuring the conductivity.