Smokeless tobacco practices are common in some parts of the world and the use seems to be increasing. Nicotine exposure is similar in smokeless tobacco users and smokers, often leading to strong physical dependence. As a rule, smokeless tobacco products contain high levels of nitrosamines with carcinogenic potency in experimental animals. Habitual use of oral tobacco can increase the risk of oral cancer, but the data are insufficient to assess in detail the risks associated with many types of smokeless tobacco. A recent study suggests that smokeless tobacco use is related to cardiovascular disease, which could be of great public health importance. The known and suspected health risks associated with the use of smokeless tobacco provide a basis for preventive action. In particular, efforts are needed to limit the introduction of such practices among young people, which may serve as a gateway to smoking.