Objective: Adolescence is a hallmark period filling with rapid changes and both positive and negative outcomes. Well-being is one of the most important outcomes should be pursued. The present study aimed to investigate the impact of family environment, academic achievement and parental expectations for educational attainment on emotional well-being among adolescents. Method: Well-being, family environment, academic achievement and parental expectations for educational attainment (PEEA) were assessed in approximately 1250 twin pairs and their parents from the Minnesota Twin Family Study (MTFS) at three points in time: 11, 14 and 17 years of age. A path analysis model was built to model the association among these variables. Multiple-group analysis was used to confirm the model and compare sex differences. A mediation analysis was conducted to specify the mediation effect of academic achievement on the association between PEEA and well-being. Results: Family environment positively contributed to well-being among 11-, 14- and 17-year-old adolescents. Academic achievement positively impacted well-being in both 11- and 14-year-old adolescents. PEEA positively contributed to well-being in 14-year-old adolescents only. The positive effect of academic achievement on family environment was significant among three age adolescents. PEEA was a powerful predictor of academic achievement. In 17-year-old adolescents, the positive effect of academic achievement on well-being was only significant for boys. Positive effects of PEEA on academic achievement and on well-being were significant for girls. Academic achievement partially mediated the positive effect of PEEA on well-being for 11- and 14-year-old adolescents and for girls during late adolescence. Conclusion: Family environment and academic achievement were two positive contributors to well-being in adolescents. Academic achievement partially mediated the positive effect of PEEA on well-being for 11- and 14-year-old adolescents and for girls during late adolescence.