There were two experiments on abstinence from smokeless tobacco. The purpose of the first experiment was to determine abstinence effects from smokeless tobacco. The purpose of the second experiment was to examine the effects of different doses of nicotine gum on smokeless tobacco abstinence effects. The subjects were male Copenhagen smokeless tobacco users who underwent 3 days of baseline measurement while continuing to use smokeless tobacco ad libitum, and 5 days of the experimental condition. In the first experiment, the subjects were assigned randomly to one of two groups and compared: continuous smokeless tobacco users (n = 10), and deprivation plus no nicotine gum (n = 10). In the second experiment, subjects were assigned randomly and in a double-blind fashion to one of three groups and compared: (1) deprivation plus 0 mg nicotine gum (n = 20); (2) deprivation plus 2 mg nicotine gum (n = 20); and (3) deprivation plus 4 mg nicotine gum (n = 20). The first experiment showed significant increases upon abstinence for the following variables: (1) craving; (2) difficulty concentrating; (3) restlessness; (4) excessive hunger; (5) eating; (6) reaction time; (7) variability of reaction time and (8) total withdrawal scores for both the self-rated and the observer-rated forms. The second experiment showed that nicotine gum failed to significantly reduce smokeless tobacco abstinence effects, although those with high cotinine levels may receive some benefit from nicotine gum.