Children between the ages of 9 and 15 are a high-risk group for tobacco use. The Centers for Disease Control estimates that first use of cigarettes among adolescents has risen 30% over the past decade, and that more than 1.2 million people age < 18 became daily smokers in 1996 alone. Moreover, research indicating that awareness and liking of cigarette advertisements is higher among adolescents than adults underscores the need to devote more effort to understanding reactions to tobacco-related messages. Adding to this problem is the fact that the early gains of some successful anti-tobacco interventions disappear as adolescents age. Drawing on the theory of psychological reactance, a number of hypotheses were tested that addressed the impact of pro- and anti-smoking messages on a variety of outcomes, including participants' intended behaviors, evaluation of message sources, and seeking of disconfirming information. All the messages were created and delivered to 4th-, 7th-, and 10th-grade students via personal computers. The pattern of results supports the theoretically derived hypotheses, indicating that grade level and message type had a significant impact on the processing of tobacco-related messages. Implications and suggestions for future tobacco prevention campaigns are discussed.