Dimensional analysis has been applied for the correlation of the thermal conductivity of a gas to its temperature, molecular weight, heat capacity, and critical constants. This approach indicates that the group k*λ/Cp should be a function of zc and TR, where λ = M1/2Tc1/6/Pc2/3. Experimental thermal conductivities of hydrocarbons at normal pressures (approximately 0.2 to 5 atm.) have been used to develop two relationships. The first is applicable to all types of hydrocarbons for 0.6 < TR < 3.0 with the exception of methane and the cyclic hydrocarbons below TR = 1.0, for which the other relationship is applicable. These two relationships have been used to calculate thermal conductivities for twenty-eight gaseous hydrocarbons for which experimental data are available. Calculated values for normal paraffins, isoparaffins, olefins, diolefins, acetylenes, naphthenes, and aromatics produce an average deviation of 2.4% from experimental values for 154 points considered.