Abstract:Participation in organized youth sports has a long-term effect and is a good predictor of factors, such as the continuation of physical activity later in life or a predisposition to be active in adulthood (Telama et al., 2005). Adolescence is regarded as a period of transition between childhood and adulthood. Adolescents must address a range of biological, social, emotional and psychological transitions to successfully enter the adulthood (Roker & Coleman, 1998), and preparing for a lifetime of physical activity is also a central aim of person (Sallis & McKenzie, 1991). The main purpose of the study was to compare cohorts of adolescent student athletes in terms of their perceptions of success, self-esteem and wellbeing. The subjects were selected from educational institutions where physical education is regarded as a formal subject and where students are under the guidance of a physical education teacher with a structured curriculum. All subjects were adolescent male students within the following broadly divided age categories (Steinberg, 1993): early (11-14 years) with a mean of 12.35 ± 1.04 years, middle (15-18 years) with a mean of 15.92 ± 1.08 years and late (19-21 years) with a mean of 19.98 ± 0.768 years. The questionnaires used in this study included the Perception of Success Questionnaire (POSQ) by Roberts, Treasure and Balague (12 items; 1998), the Rosenberg Self-Esteem Scale (RSE) (10 items; 1965), and the well-being questionnaire by Birleson (18 items, 1980). Descriptive statistics were used to analysis the result. To determine the correlations among the variables, Pearson's correlation was used; to compare the cohorts, we used one-way ANOVA. The results showed significant differences in all of the psychological factors, including success, self-esteem and well-being, between the early, middle and late adolescent students.