Mental health and well-being among high-performing male and female engineering students were investigated to account for variance. A self-report survey was used to assess mental health and well-being, and the results of the end-of-year evaluation were used to measure academic accomplishment. This study was unique in that it created the self-reported survey from a developmental viewpoint (i.e., developmental strengths, constructive skills, and psychological competencies) using the normative-crisis model and the psycho-social model of development. Of the 152 (121 male, 31 female) University students from Chile, twenty high-achieving male and female students were randomly selected. The findings showed that female students scored lower in all subjects, reported lower levels of hope and reported more mental health concerns than male students. Structural equation modelling (SEM) analysis of female students' results found that lower hope levels and higher developmental strengths were associated with high academic achievement. However, mental health issues and psychological competencies among females did not influence higher achievement. In contrast, SEM analysis of male students' results found no correlation between academic achievement and mental well-being, which suggests that high academic achievement is independent of sex differences, mental health and well-being. Insights, implications and recommendations are discussed.