Is nicotine more addictive than cocaine? That claim is increasingly in vogue, often supported by data showing the high likelihood of progression to daily tobacco use following experimentation and the high percentage of cigarette smokers, compared with cocaine users who appear addicted. In the context of criteria for addiction of dependence presented by the World Health Organization, the American Psychiatric Association, and the US Surgeon General, we consider several lines of evidence, including patterns of mortality, physical dependence potential, and pharmacologic addiction liability measures. Within each line of evidence, we compare nicotine with cocaine. We conclude that on the current evidence nicotine cannot be considered more addicting than cocaine. Both are highly addicting drugs for which patterns of use and the development of dependence are strongly influenced by factors such as availability, price, social pressures, and regulations, as well as certain pharmacologic characteristics.