This study was a prospective examination of tobacco withdrawal symptoms in a controlled environment. Smokers (N = 27) were hospitalized for a 7-day period during which a battery of tests was administered. Smokers were assigned to either an experimental group (N = 20) or a control group (N = 7). Subjects in the experimental group smoked ad libitum for a 3-day baseline period and then underwent 4 days of tobacco deprivation. Subjects in the control group continued to smoke ad libitum throughout the study. Of the 37 measures of tobacco withdrawal employed in this study, nine showed significant changes following tobacco deprivation. These changes include decreased heart rate and increased caloric intake, weight, craving for tobacco, confusion, depression-dejection, number of awakenings, duration of awakenings, and increased poor concentrations as observed by others.