In previous calculations of the resistivity the iterative series of the total T matrix of the system has been truncated so that multiple scattering effects have been neglected. In an attempt to include such effects the T matrix is obtained here within the quasicrystalline approximation, resulting in a modified Ziman formula in which the scattering cross section now includes the effects of multiple scattering. Application is made to the liquid metals V, Cr, Mn, Fe, Co, Ni, Cu, Pt, Pd, Ag and Sn, showing good agreement with experiment.