Many adolescents want to quit and have specific ideas on how they want to go about it. This study extended the search for factors related to different aspects of quitting. Four cross-sectional surveys of Queensland (Australia) secondary schools every three years over the past decade (1993, 1996, 1999, and 2002). A total of 9993 school students in grades 8 to 12 completed the survey. The data for 2451 students who had smoked in the last week (51% female) were used for the analysis of smoking cessation outcomes. The outcome measures for the study represented various smoking cessation outcomes, such as a desire to quit, attempts to quit, quitting for a week or more, and an intention not to be smoking in the following year. More than 60% of adolescent smokers are involved in the process of smoking cessation. The strongest predictor of cessation was whether or not students had actively influenced other students not to smoke. This finding supports the concept of involving adolescents more actively in prompting their peers to try quitting and supporting their efforts to quit smoking.