Smokeless tobacco products are a known cause of oral cancer in India. Carcinogenic tobacco-specific nitrosamines in these products are believed to be at least partially responsible for cancer induction, but there have been no recent analyses of their amounts. We quantified levels of four tobacco-specific nitrosamines- N’-nitrosonornicotine (NNN), N’-nitrosoanatabine (NAT), N’nitrosoanabasine (NAB), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)- in 32 products currently marketed in India. Levels of nitrate, nitrite, and nicotine were also determined. The highest levels of tobacco-specific nitrosamines were found in certain brands of khaini, zarda, and other smokeless tobacco products. Concentrations of NNN and NNK in these products ranged from 1.74-76.9 and 0.08-28.4 μg/g, respectively. Levels of tobacco-specific nitrosamines in gutka were generally somewhat lower than in these products, but still considerably higher than nitrosamine levels in food. Tobacco-specific nitrosamines were rarely detected in supari, which does not contain tobacco, or in tooth powders. The results of this study demonstrate that exposure to substantial amounts of carcinogenic tobaccospecific nitrosamines through use of smokeless tobacco products is still a major problem in India.