The evaluation of the electrical resistivity of binary liquid alloys requires the true knowledge of the partial structure factors as well as the form factors of the constituent species. In principle partial structure factors are measurable, but the practical difficulties are severe and it is not promising to use the measured data. We, therefore, consider a simple theoretical approach based on hard sphere reference system and the Percus—Yevick equation to compute the partial structure factor. The concentration dependence of the hard sphere parameters are obtained by minimising the Helmholtz free energy of the system following the Gibbs—Bogoliubov variational technique. We have used it to compute the concentration dependence of electrical resistivity of NaK, KRb and NaCs liquid alloys. Our study reveals the like particle correlation contributes positively to the absolute value of electrical resistivity while the unlike particle correlation makes a negative contribution.