Dianin's Compound (4-p-hydroxyphenyl-2,2,4-trimethylchroman) has been shown to demonstrate a marked selectivity when it forms clathrates from binary alcohol solutions. The relationship between solvent composition in solution and in the crystalline adduct was found to be linear in all but one case. The degree of selectivity was expressed quantitatively as the “preference index.” Results obtained indicated that the molecular shape of a potential guest plays a dominant role in the formation of Dianin's Compound adducts.