Measurements of the thermal conductivity of propane performed in a coaxial cylinder cell operating in steady state conditions are reported. The measurements of the thermal conductivity of propane were carried out along eight quasi-isotherms above the critical temperature. The present data cover the temperature range from (370.83 to 381.00) K, and the pressure range (0.1 to 15) MPa. An analysis of the various sources of error leads to an estimated uncertainty of approximately 3 %. The parameters of a background equation were determined from experimental data in order to analyze the critical enhancement of the thermal conductivity as a function of temperature and density. On the basis of the measurement of more than 500 experimental points, a phenomenological equation is provided to describe the thermal conductivity of propane, from the critical temperature 369.825 K to 600 K and densities up to 550 kg·m–3. This equation can be generalized to calculate the supercritical behavior of the thermal conductivity for any fluid.