Continuous wave and pulse NMR measurements were carried out on phenol derivatives containing t‐butyl groups [tri‐t‐butylphenol (TTBP), methylene‐bis(2,6‐di‐t‐butylphenol) (MBBP), and the galvinoxyl radical] to investigate the molecular motions of methyl and t‐butyl groups. From second moment measurements we distinguish three temperature regions characteristic of different forms of molecular motions. Between the rigid‐lattice limit (plateau region III) and plateau region I at high temperature where both methyl and t‐butyl motions are present, there appeared shoulders in the second moment curve. The shoulders in the second moments and relaxation minimum at low temperature are satisfactorily explained by the motional model which includes nonequivalent methyl motions; two methyls in each t‐butyl group at the ortho positions and all methyls in the t‐butyl group at the para positions are responsible for these phenomena, while one methyl motion in each t‐butyl group at the ortho positions and the entire motion o...