The nuclear magnetic resonance spectra of the alkyl-substituted pyridines found in the tar bases from a hydrocracked crude shale oil are discussed mainly with respect to the chemical shifts, but where possible the coupling constants'are given for individual proton resonances. A determination of the chemical shift of various alkyl groups attached to the pyridine nucleus permits the identification of various alkyl-substituted pyridines where the gross fraction has been partitioned into simple mixtures by gas chromatography.