This mixed methods study investigated the relationship between young people's vocational aspirations and their adult occupations using three datasets collected at different times across a twenty year time span. Data from two studies of the same cohort of 858 longitudinal study participants (as teens, in 1986/7 and at age 32, in 2004/5) were used to compare aspirations and occupations. The results showed that less than a fifth of participants worked in the actual adult occupation that they had aspired to as a teenager, despite their overall confidence in their ability to obtain their desired occupation. However, having some type of teenage vocational aspiration was important for adult occupational outcomes: having a teenage aspiration was significantly associated with working in managerial or professional occupations as an adult. The participants in this study were more likely to have managerial jobs, trades or unskilled occupations than they had expected as teens. It was also the case that teenagers who had managerial or professional aspirations were more likely to work in these types of careers than those with other types of vocational aspirations. The data showed a significant difference in the aspirations and occupations by gender. Nearly all the teenage boys aspired to male-dominant occupations and most of them worked in male-dominant occupations as adults. Girls were much more likely to aspire to occupations across the gendered spectrum. Nearly half of the adult women worked in female-dominant occupations. The women who had non-female dominant careers were more likely to be cognitively advantaged and come from families with higher socio-economic status. This suggests that crossing the gendered occupational boundary is particularly challenging for girls from disadvantaged backgrounds and for boys. The third dataset was collected from 91 young people across three New Zealand sites in the early 21st century using in-depth interviews. The data from this project was analysed using three different methods to identify some of the reasons for the differences in aspirations and occupations identified in the other study. The majority of this cohort also changed their vocational plans despite the period of time between interviews being considerably shorter than that of the other cohort. The results showed that young people's vocational behaviour was influenced by chance and unplanned events such as health issues, family crises and failing to meet the pre-requisite requirements for courses. Many young people's vocational dreams were also restricted by their limited access to economic, social and cultural resources. Many young women faced the challenge of balancing success in both traditionally male and female domains. The social, economic and political climate provides an inequitable environment in which young people have access to different levels of resources. As a result, many young people are unable to follow their vocational aspirations.