Chiral gas chromatography-mass selective detection has been successfully employed in the analysis of secondary alkaloids in selected tobacco, materials and cigarette smoke condensate. No extensive sample preparation is involved. A lower detection limit of ~ 2 % d -nornicotine, d -anabasine and d -anatabine in a mixture of l and d isomers was achieved. The levels and the enantiomeric ratios of nicotine, nornicotine, anabasine and anatabine varied in different tobacco types. The enantiomeric ratios of nicotine, anabasine and anatabine in mainstream cigarette condensate also varied but were generally representative of the enantiomeric ratios for the alkaloids found in the leaf. The enantiomeric ratio for nornicotine in mainstream cigarette condensate also varied and was not representative of the enantiomeric ratios for the alkaloids found in the leaf. Preferential decomposition or racemization may account for the differences seen in the yields of isomers of nornicotine transferred to the mainstream smoke condensate. An experimental was conducted to determine if the d -nornicotine present in tobacco contributed to the yield of d -nicotine in mainstream smoke condensate. The results of that experiment indicated that yield of d -nicotine transferred to mainstream smoke dit not change significantly when either large levels of endogenous nornicotine were present in the leaf or when large levels of exogenous levels of d -, l -nornicotine were applied to the tobacco rod prior to smoking. The limiting factor in the production of d -nicotine in mainstream cigarette smoke condensate may be the concentration of methyl radicals present to react. Further work must be conducted to unravel the mechanism involved in the production of d -nicotine in cigarette smoke condensate.