The gas chromatographic method was employed to measure the infinite dilution activity coefficients of twenty-eight hydrocarbons of different types in di-n-octyltin dichloride between 323.15 and 353.15 K, and ofseven branched alkanes in tri-n-octyltin chloride between 313.15 and 333.15 K. A comparison is made between the results obtained for all the solutes in both solvents and in tetra-n-octyltin.