A complete analysis is given of the nine-spinproton magnetic resonance spectrum of p-methylbenzyl bromide as a 20 mol% solution in acetone-d6 The long-range coupling constants between methyl and ring protons are the same as those in toluene. The coupling constants between the methylene protons and the other protons in the molecule are consistent with a two-fold barrier of 500 ± 200 cal/mol for the bromomethyl group, the preferred conformation having the C—Br bond in a plane perpendicular to the aromatic plane. An alternative model, in which a C—H bond of the bromomethyl rotor prefers the aromatic plane to the extent of 3 kcal/mol, is considered unlikely.