The solid-state low-temperature C-13 NMR spectra of 1-(methyl-C-13)-1-methylcyclohexane, cis-1-(methyl-C-13)-3,5-dimethylcyclohexane, and trans-1-(methyl-C-13)-3,5-dimethylcyclohexane have been measured and the principal values of the C-13 chemical shift. tensors are reported for the labeled methyl carbons. The orientation of the principal axes of the chemical shift tenser has been estimated using ab initio calculations of the tensors. The calculated shift tensors for the axial and equatorial isomers of methylcyclohexane, which are also presented in this paper, are almost identical to those from the 3,5-dimethyl-substituted compound. This indicates that chemical shift tensors for a methyl group are primarily determined by local electronic and steric factors. Changes in steric effects and beta-substituent effects between axial and equatorial methyls on the cyclohexane ring are discussed in terms of their effect upon chemical shift tensors in these paraffin hydrocarbons.