A simple extension of the rough hard-sphere theory is proposed to describe the thermal conductivity and viscosity of a wide variety of polar compounds. The method is based on the known transport properties of a smooth hard-sphere system together with a temperature-dependent hard-core volume and coupling parameters to account for deviations from true smooth hard-sphere behavior. A key advantage of the method is the ability to simultaneously correlate self-diffusion, viscosity, and thermal conductivity using a common characteristic volume V-0 for each compound. Thus, information about V-0 obtained from one transport property can be applied to calculate the other properties. The model is also well suited for extension to temperature and pressure conditions outside those at which experimental data are available. Results for 58 polar liquids in the temperature range from 293 to 493 K are presented with a maximum error of 5.0% for viscosity and 2.9% for thermal conductivity. Model parameters for a homologous series of compounds can be expressed as smooth functions of the size, allowing the prediction of the transport properties for compounds for which data are presently not available.