In Australia, as in most English-speaking countries, increasing numbers of children with significant hearing loss are being educated in regular classes with the support of itinerant teachers of the deaf, rather than in segregated settings. These students primarily use their amplified residual hearing and communicate orally, and may be functionally defined as hard of hearing. This thesis reports on a study investigating the career development of hard of hearing high school students attending regular Year 10, 11, and 12 classes with itinerant teacher support in the Australian states of Queensland and New South Wales. The students had bilateral sensorineural hearing losses ranging from mild to profound. The study sought to identify and analyse the key factors that influence the career development of this population. The design of the study was informed by Social Cognitive Career Theory (Lent, Brown, & Hackett, 1994), with its emphasis on cognitive variables, personal agency, diversity, and contextual influences, and the developmental theory of Donald Super and its associated concept of career maturity (Super, 1980; Super, Savickas, & Super, 1996). The study also investigated the social participation of hard of hearing adolescents and the relationship among the students' perceptions of their social participation, their social self-concept, and their career decision-making. The research was conducted using a three-phase, mixed methods approach incorporating two major phases, one quantitative and one qualitative, preceded by a minor, preliminary phase. The preliminary, exploratory phase of the study was included in order to guide the design of the survey instrument, and in particular the section covering perceived career barriers, an area not discussed in the literature for this population. Interviews were conducted with four hard of hearing Year 12 school students and four hard of hearing first-year university students who were recent school-leavers. In phase two, sixty-five hard of hearing students were compared with a matched group of normally hearing peers on measures of career maturity, career indecision, perceived career barriers, social participation and three variables associated with Social Cognitive Career Theory: career decision-making self-efficacy, outcome expectations, and goals. In addition, predictors of career maturity were tested for both groups. Phase three comprised the collection and analysis of qualitative data from interviews with a proportion of the survey respondents to explore the quantitative results in greater depth. Twelve students with hearing losses ranging from moderate to profound participated in these interviews. Results of the quantitative analysis indicated that (a) the two groups did not differ on measures of career maturity or social participation, (b) the Social Cognitive Career Theory variables were less predictive of career behaviours for the hard of hearing students than for the normally hearing students, and (c) perceived career barriers related to hearing loss predicted lower scores on the measure of career development attitudes for the hard of hearing students. The quantitative data also showed that survey respondents reported high levels of anticipation of some hearing-related barriers to achieving their educational or career goals, particularly 'people not understanding my hearing loss.' The results of the qualitative analysis extended many of the quantitative findings, yielding information and insights inaccessible through traditional quantitative methods. The qualitative findings revealed ways in which students perceived potential barriers, how they felt about them, and ways in which their perceptions of barriers influenced their career choice and decision-making. In addition, the qualitative findings revealed a complex interaction among students' social participation with their peers, their experiences of other people's negative reactions, their self-consciousness about their hearing loss, their fears about mishearing people, and their career decision-making. In sum, the study identified potential career barriers as a key factor influencing the career development of this group of hard of hearing students, and clarified understanding of the way in which their social self-concept interacted with their career development. The study's findings contribute to current knowledge and understanding of the career development of adolescents with significant hearing loss who attend regular classes with itinerant teacher support in two states of Australia. The thesis discusses implications for theory and for practice that have arisen from the study, and sets out recommendations for ways in which the career development and transition of this population might be improved.