A method is proposed to predict the liquid thermal conductivity of HCFC and HFC refrigerant mixtures, using the thermal conductivities, the molecular weights, the mass and mole fractions, the critical temperatures and the dipole moments of the components. The method can also be extended to mixtures of n-paraffin hydrocarbons. The method was checked against experimental data in the literature and compared with other prediction methods. The results showed that the present method is more accurate than other methods, though its form is very simple. The relative deviations of the predicted thermal conductivities from the experimental data are <2%, which is sufficiently accurate for engineering applications.