Adolescence involves multiple academic changes and increased challenges with potential dramatic effects on student motivation and learning. This chapter focuses on the influence of one motivational process, perceived self-efficacy. The chapter provides background information on self-efficacy related to the larger theoretical framework of human action: social cognitive theory. The bulk of the chapter examines the academic self-efficacy beliefs of adolescents, tracing current research findings on self-efficacy beliefs, the key roles played by significant persons in the adolescent's environment, and interventions designed to improve self-efficacy. The chapter explains how judgments of capability for learning or performing behaviors at designated levels are powerfully related to the academic success that students experience, as well as to other motivation constructs and processes. Throughout the chapter, references are made to challenges to adolescents' self-efficacy that can negatively affect motivation, focusing on how students respond to failures and how teachers can help them "bounce back" from academic setbacks. (Contains 70 references.) (KB)