The methyl resonance patterns of some isopropylcarbinols and isopropyl esters are described and discussed. The important influence of a phenyl nucleus on these patterns is obvious. The presence of such a nucleus as well as that of an asymmetric centre is a prerequisite for doubling of the methyl doublet in the case of the esters. It could not be established whether the doubling is due to intrinsic asymmetry, to preferential conformations, or to both factors.