Theoretically derived career education programs are not well documented in the career development literature. This remains so, despite growing recognition of the negative effects of a schism between theory and practice. This thesis describes a research project that attempted to incorporate theory into practice. The two primary aims were to test and extend career development theory, and to evaluate a theoretically derived career education program. The participants were 296 Year 10 students (mean age = 14.5 years; 147 females & 149 males) attending a government high school in a low socio-economic area of a large Australian city. Career maturity, career decision-making self-efficacy, and career indecision were the key career development variables examined. Students' decision coping patterns were also investigated. There were three studies in all. The first gathered qualitative data from a stratified random sample (N = 30) of staff and parents at the school where the research took place. This study assessed the career decision-making development needs of the students. It also provided context specific information about the opportunity structure of these adolescents, including perceived barriers to making sound career-related decisions. Findings centred upon the belief that students lacked self confidence and were in need of training in life skills generally, and decision-making and goal setting skills in particular. The interviewees also painted a grim picture about students' complacency and sense of resignation to unemployment. The second study involved the cross-sectional examination of baseline survey data, which obtained measures of the career development variables under investigation as well as relevant demographic and contextual data including part-time work experience, school achievement level, and parents' education and employment status. A thorough review of the career development literature, combined with the qualitative data, and the findings of this cross-sectional study, served to guide the design of a career education intervention. Social cognitive career theory's choice model (Lent, Brown, & Hackett, 1994) was used as the framework for the career education intervention, which ran for six weeks with one 70 minute lesson per week. Relationships amongst the key variables established previously in the literature were reflected in the results of the cross-sectional study. Demographic and contextual variables were also found to impact upon students' level of career development and decision-making behaviour in anticipated ways. The third study was a longitudinal assessment of the intervention using the baseline survey and three more surveys administered during the same school year. The short and long term effects of the intervention were examined according to mode of delivery, and comparisons were made with controls. The researcher was the career development "expert" facilitator for the implementation of the intervention to 134 students between the first and second testing times. A wait-listed control group of 118 students undertook the intervention between the second and third testing times with regular classroom teachers facilitating it. The remaining students were enrolled in a generic school-based vocational course and were not given the intervention. There was a lapse of eight weeks between each of the first three testing times with the fourth test taken 12 weeks later. Despite its brief nature, the intervention was found to assist students' career development in a variety of ways. It led to gains in career maturity for females regardless of who taught them. However, males' career maturity was enhanced only if teachers facilitated the intervention. Levels of career indecision and maladaptive decision-making coping patterns were also reduced by the intervention with teacher facilitation. A matched sample of students who did the intervention exhibited significantly better outcomes than those doing the generic vocational course. The long term impact of the intervention was found to be generally beneficial, although some gains were not maintained 12 weeks later. Students' career decision-making self-efficacy and their resoluteness toward decision-making were not affected by the intervention. The research findings led to an appeal for the realignment of focus in career education. This has implications for career education curriculum development in Australia, which needs to shift from its ad hoc, information giving approach, to more comprehensive, long-term, and intensive programming. Career education that enhances the personal skills students need to meet the demands of the world of work in the twenty-first century is required. Career process skills are of paramount importance. Specialist training for career guidance officers is also recommended and more research incorporating theory and practice is advocated.