A range of research has recognized the benefits of optimism in a variety of health-related outcomes. Pessimism has received less attention but may be a distinct concept that is uniquely related to certain health behaviors, including drug use. The present study examined relationships between optimism and pessimism and alcohol use trajectories of adolescents using latent growth modeling. Results suggest that optimism was negatively associated with alcohol use at age 14, but pessimism was negatively associated with alcohol use at that age for boys. Findings illustrate the importance of perceptions about the future to patterns of alcohol use at younger ages. (Contains 1 figure.)