The study of the role of students' interest in their learning has seen a resurgence in the past 20 years. This chapter examines the ways in which adolescents' interests develop, differ from those of younger children, and contribute to their developing sense of self. The chapter helps to explain why many adolescents lack academic interests and how their interests can be related to antisocial behavior. The chapter also describes how vocational interests may play critical roles in their lives, given that individuals are required to make career and lifestyle decisions during adolescence. Following introductory remarks, the chapter describes situational interest as a state involving focused attention, persistence, and increased cognitive functioning, and differentiates it from individual interest, a relatively enduring predisposition to engage in particular activities. The development of individual interest and its relationship to achievement, self concept development, and identity formation are described. It is argued that understanding adolescents' individual and occupational interests will inform the study of identity formation and the development of a sense of self. The chapter presents models of vocational interest development. The contribution of patterns of individual interests and occupational interests to adolescents' status as at-risk for school dropout is discussed. It is asserted that educators need to understand the extent to which interest contributes to adolescents' developing sense of self because it impacts on their responsiveness to school experiences. The chapter concludes by noting that student interest is more likely to persist if individuals attach the new experience to themselves, thereby making it an individual interest. (Contains 115 references.) (KB)