For cyclohexylmethyl and 4-alkylcyclohexylmethyl radicals the conformer in which the CH₂˙ group adopts the axial position and that in which the CH₂˙ group adopts the equatorial position can both be observed by e.s.r. spectroscopy. At 140 K the axial conformers have a(H_β)ca. 42–43 G; the equatorial conformers have a(H_β)ca. 30–31 G. For cis-4-methylcyclohexylmethyl radicals the ratio of the concentrations of the two conformers was studied as a function of temperature and shown to depend on the rate of radical ring inversion vs. the radical lifetime; the rate constant for ring inversion was obtained. As a check on the e.s.r. results the conformational equilibrium of cis-4-methylcyclohexylmethyl bromide was studied by ¹H n.m.r. spectroscopy, which gave –ΔG°₃₀₀(CH₂Br)= 1.91 kcal mol^–1. The relative conformer concentrations were also measured as a function of temperature for cyclohexylmethyl radicals and the conformational free energy difference of the CH₂˙ group (–ΔG°₃₀₀) was found to be 0.71 kcal mol^–1. The preponderance of the conformer of the cis-4-methylcyclohexylmethyl radical with the CH₃ group axial at T < ca. 175 K was attributed to the fact that the axial non-rotating CH₃ group can adopt a staggered, minimum-energy conformation, whereas the axial non-rotating CH₂˙ group cannot because of its planarity. The barriers to rotation about the C_α–C_β bonds in the axial radicals were found to be ca. 1.0 kcal mol^–1 greater than those of the equatorial radicals; this is responsible for the greater a(H_β) values of the axial radicals. The axial and equatorial conformers of cyclohexylmethyl radicals were investigated by semi-empirical SCF MO methods.