This cross-sectional study investigated self-esteem in relation to age, gender, ethnicity, and risk behaviors among a sample of nonmainstream students. Participants were 149 students in the 6th to 12th grades from two non-mainstream schools (one charter and one alternative school). Self-esteem and youth risk behaviors were determined by using a modified version of the Rosenberg Self-Esteem Scale (Rosenberg, 1965) and the National Alternative High School Youth Risk Behavior Survey (Grunbaum et al., 1999), respectively. Results indicated that non-mainstream students with high self-esteem were more likely to engage in their first sexual experience and to begin marijuana use later in life. African American students reported having their first sexual experience at an older age, but having more sexual partners than did Latino students. The implications of these findings are discussed. Self-esteem can be an important component of an adolescent's healthy development and successful transition to adulthood (e.g., Chubb, Fertman, & Ross, 1997). Self-esteem is defined as a person's feeling of self-worth (Rosenberg, 1965) or a person's view of his or her competency and worthiness (Overholser, Adams, Lehnert, & Brinkman, 1995). While high self-esteem may be associated with an overall sense of well-being during adolescence, low self-esteem has been related to risk behaviors and negative developmental outcomes. For instance, young people with low self-esteem are at high risk for attempting suicide. Several studies have shown that adolescents with low self-esteem have elevated levels of suicidal ideation and negative expectations of the future (e.g., McGee, Williams, & Nada-Raja, 2001; Overholser et al., 1995).