The situation concerning adolescent mental health is a global public health concern, and the concept includes the ability to cope with problems of everyday life. A person’s approach and attitude towards themselves, i.e., their self-esteem, affects mental health. The study aimed to appraise and deepen the scientific understanding of adolescents’ self-reported self-esteem at age 12−13 from a resource perspective and test its ability to predict subsequent perceived mental well-being at age 17.

Data from the Longitudinal Research on Development in Adolescence (LoRDIA) prospective follow-up study of adolescents aged 12−13, and 17 (n = 654) were analysed using ANCOVA. The outcome variable, perceived mental well-being (MWB), covers the aspects of mental well-being inspired by the “Mental Health Continuum,” representing positive mental health. Covariates were self-esteem (SE) and reported initially perceived MWB at age 12−13. Other independent explanatory variables were gender, the family’s economy, and the mother’s educational level.

Self-esteem appeared relatively stable from 12−13 to 17 years (M = 20.7 SD = 5.8 vs. M = 20.5 SD = 1.7). There was a significant but inverted U – shaped association between SE at age 12–13 and perceived MWB at age 17 [F (1, 646) = 19.02, β-0.057; CI -0.08−-0.03, Eta = 0.03, p = .000]. Intermediate but not strong SE predicted significantly good MWB. When conducting the ANCOVA for boys and girls separately, only the mother’s educational level was significantly positively associated with perceived MWB of girls.

Good self-esteem in early adolescence increases the likelihood of an unchanged favourable development of self-esteem and the probability of good perceived mental well-being. SE explained 18 per cent of the variation of MWB, and even more among girls. However, normal SE rather than high SE at 12 and 13 years is predictive of later mental well-being. Girls reported low self-esteem more often. Therefore, supporting self-esteem early in life can promote mental well-being in adolescence.