Fourteen liquid phases thought to be stable at high temperatures have been surveyed for separation of the linear hexadecenes from a large excess of of n-hexadecane. Carbowax 20M and its modifications were found most satisfactory and of the modifications examined, only treatment with terephthalic acid gave a detectable improvement. Retention times, determined at four temperatures, were most characteristic for those structural isomers in which the position of unsaturation was nearest the end of the hydrocarbon chain. For those positional isomers in which differences in retention times were discernable, the cis-configuration was invariably retained longer than the trans.